She turnned pro at the end of 2019 and joined the Symetra Tour. In her first event in early March, she finished tied for third, and things looked promising. However, shortly after that, the worldwide Covid pandemic hit, and Hong went home to Korea. She did not play again the entire year.

Amy returned to action on the Symetra Tour in 2021. She wasn't able to get a win, but she did have a runner up and five other top tens. She was close enough to earning her card by finishing in the top ten that she could have done it with a strong finish at the year's final event, but alas she had a bad week and wound up 16th on the money list.

She instead went to Q Series and had a great two weeks, eventually finishing 12th and easily securing full status for the LPGA's 2022 season.

Hong also played twice on the KLPGA in 2021. Her better finish was an 11th at the SK Networks in late October. She finished 39th at the other event.

Hong's rookie year was not that great. She had a streak of seven missed cuts in the summer, and other than a couple of early top 25 finishes, she struggled. She ended the year in an interesting way. In her return to Korea at the BMW Championship, she shot a first round 66 and ended up tied for 10th, easily her best finish of the year. She next played at the Pelican, where she shot her career best score of 65 in round one. Alas, she struggled the rest of the week and finished tied for 68th.

She had to return to Q-Series, but was only able to secure limited access to the tour for 2023. She played a few events on the LPGA in 2023 but had little success. She did have a top 20 when paired at a team event with Hae Ran Ryu, but otherwise missed most cuts. As a result, she returned to Korea, where she qualified for the KLPGA in 2024. It will be interesting to see if her rookie year in Korea is more successful than her LPGA rookie season was; it's rare for someone to join those tours in that order.