You can't stop finasteride too if you don't want to lose hair and if you stop minoxidil after some time, you will only lose minoxidil dependent hair and after stopping it your hair will be same as if you had never used minoxidil.
I had a slow receding hairline since when I was 15 years old with a big forehead that made it look more bad. I started minoxidil 5% once a day in November 2018, then I switched to Morr f5 that is topical finasteride 0.1%+5% minoxidil in May this year.