Theory:

Epiphora is a type of repetition. Unlike anaphora, epiphora appears at the end of a sentence, stanza, or paragraphs. It is also known as Epistrophe.
Pronunciation Guide
Epiphora: E (as in "any")-- pi (as in "pillow")-- pho (as in "phone")-- ra (as in "Dora")
Let us look at the poem "O Captain, My Captain" by Walt Whitman.
Example:
O Captain! my Captain! our fearful trip is done,
The ship has weather’d every rack, the prize we sought is won,
The port is near, the bells I hear, the people all exulting,
While follow eyes the steady keel, the vessel grim and daring;
But O heart! heart! heart!
O the bleeding drops of red,
Where on the deck my Captain lies,
Fallen cold and dead.
 
O Captain! my Captain! rise up and hear the bells;
Rise up—for you the flag is flung—for you the bugle trills,
For you bouquets and ribbon’d wreaths—for you the shores a-crowding,
For you they call, the swaying mass, their eager faces turning;
Here Captain! dear father!
This arm beneath your head!
It is some dream that on the deck,
You’ve fallen cold and dead.     
                  
My Captain does not answer, his lips are pale and still,
My father does not feel my arm, he has no pulse nor will,
The ship is anchor’d safe and sound, its voyage closed and done,
From fearful trip the victor ship comes in with object won;
Exult O shores, and ring O bells!
But I with mournful tread,
Walk the deck my Captain lies,
Fallen cold and dead.
The phrase "fallen cold and dead" is a refrain which appears at the end of every stanza. Hence, this repeated line "fallen cold and dead" is the epiphora here.
 
Let us take another example of epiphora. In the poem called "Vocation" by Rabindranath Tagore, the phrase "Bangles, crystal bangles" is repeated twice in the poem's first stanza. The following is an extract from the poem.
Example:
When the gong sounds ten in the morning and
I walk to school by our lane,
Every day I meet the hawker crying,
Bangles, crystal bangles!”

There is nothing to hurry him on, there is no
road he must take, no place he must go to, no
time when he must come home.
I wish I were a hawker, spending my day in
the road, crying, “Bangles, crystal bangles!”
In the following example, epiphora appears in a slightly different way. Let us see how it happens.
Example:
I quarrelled with my brother
I don’t know what about,
One thing led to another
And somehow we fell out.
The start of it was slight,
The end of it was strong,
He said he was right,
I knew he was wrong
!

We hated one another.
The afternoon turned black.
Then suddenly my brother
Thumped me on the back,
And said, “Oh, come along!
We can’t go on all night —
I was in the wrong."
So he was in the right
.
The above poem is called "The Quarrel" by Eleanor Farjeon. In this poem, the lines "He said he was right/I knew he was wrong!" and "I was in the wrong/So he was in the right" can be called epiphora even though they are not word-to-word repetition. It is because the lines give a feeling of being repeated, which also adds a good rhythm to the poem.
Hence, if the repetition is at the end, it is called Epiphora.
Epiphora used in the poem "The Shed":
There’s a shed at the bottom of our garden
With a spider’s web hanging across the door,
The hinges are rusty and creak in the wind.
When I’m in bed I lie and I listen,
I’ll open that door one day.
 
There’s a dusty old window around at the side
With three cracked panes of glass,
I often think there’s someone staring at me
Each time that I pass,
I’ll peep through that window one day.
 
My brother says there’s a ghost in the shed
Who hides under the rotten floorboards,
And if I ever dare to set foot inside
He’ll jump out and chop off my head,
But I’ll take a peek one day.
 
I know that there isn’t really a ghost,
My brother tells lies to keep the shed for his den;
There isn’t anyone staring or making strange noises
And the spider has been gone from his web
since I don’t know when,
I’ll go into that shed one day soon,
 
But not just yet...
The phrase "one day" appears at the end of every stanza. Hence, this is an example of epiphora.
    Reference:
  • https://www.poetryfoundation.org/poems/45474/o-captain-my-captain
  • National Council of Educational Research and Training (2006). Honeysuckle. Vocation-Rabindranath Tagore (pp. 109). Published at the Publication Division by the Secretary, National Council of Educational Research and Training, Sri Aurobindo Marg, New Delhi.
  • National Council of Educational Research and Training (2006). Honeysuckle. The Quarrel- Eleanor Farjeon (pp. 39). Published at the Publication Division by the Secretary, National Council of Educational Research and Training, Sri Aurobindo Marg, New Delhi.
  • National Council of Educational Research and Training (2007). Honeycomb. The Shed: Frank Flynn (pp. 48 -49). Published at the Publication Division by the Secretary, National Council of Educational Research and Training, Sri Aurobindo Marg, New Delhi.