Agree with naps too

Lay her down when she is really sleepy. I started it off with nap time and after three days he was a pro. No crying

Try propping her up some, my son would not sleep flat on his back so he slept in his swing until he was around 3 months then I transitioned him to a bassinet with a wedge beneath the mattress to prop him up enough that he wasn't laying flat. Then when I transitioned him to the crib I started laying him on his tummy (he was about 4 and a half months old) because he would sleep almost thru the night on his tummy, I would just get up to check on him more often 😂

Start with naps