To unlock the A Poet's Tale trophy in Assassin's Creed Odyssey, you need to have Update 1.1.2 installed and have completed at least Chapter 5 of the main quest.
The first quest of this arc, Praxilla's Admirer, can be found in the Mount Helikon region of Boeotia. The closest viewpoint is called Standing Pillar. It will be highlighted on the map with a blue diamond with an exclamation mark in the middle.
You will be asked by Orchimedes to find five coral roses which are located to the north on top of a hill. Once at the top of the hill, you will have to fight three wolves. Once you have killed them, collect the coral roses and return to Orchimedes. Once you have finished the dialogue, you will be asked to take the coral roses to Praxilla. Deliver the roses by talking to Praxilla, during the cutscene Praxilla's Lyre will be stolen and you will be asked to retrieve it.
You will have to speak to people in the camp to find clues. Speak to Krantor and he will tell you to speak to the servant girl and Orchimedes in the Temple of Athena Itonia in the northwestern part of Mount Helikon. The servant girl can be found on the road to the south of the temple. Speak to her and she will tell you that Orchimedes has been taken by bandits and you will be tasked with freeing him. Once you have killed the bandits and freed Orchimedes, you will have to escort him from the area and talk to him.
You will have to make two decisions during the conversation. The choices you make won't cause you to miss the trophy, so choose as you wish.
Once the conversation is over, he will give you Praxilla's Lyre. Return to Praxilla and talk to her to complete the quest.
Repairing the Lyre
Talk to Praxilla again to begin the quest and then follow her to the Port of Kreusis. Once you arrive, talk to Praxilla again and you will be asked to retrieve items to repair the Lyre.
Gather three wolf intestines:
No marker will be displayed on the map, but head to Narkissos which can be found to the west of the village. Kill the wolves and loot them to gather the intestines.
Gather three shells:
Next, you will need to find three shells on the beach to the south.
Gather silver birch:
You can find the silver birch to the east of Port of Kreusis.
Once you have collected three of each item, return to Praxilla and talk to her.
Return to Praxilla's camp and talk to her again to begin Praxilla's Legacy. Escort her to the stage located near Port of Kreusis. Once you arrive, she will ask you to recite her poem. There is no way to fail regardless of which options you choose.
If you want to please Praxilla and the crowd, the correct lines to the poem are:
The most beautiful thing I leave is the light of the sun.
Second are the shining stars and the face of the moon.
Then ripe cucumbers, apples, and pears too.
Once you have finished reciting the poem, the crowd will be attacked and you will have to protect Praxilla. Once you have defeated the thugs, talk to Praxilla again to complete the quest.