Crawl to her, fill a plastic coke bottle with lentils/pasta/rice, shake it to get her attention, roll it around (lots of sellotape around lid so it can't fall off). Lots of praise and encouragement. I recall putting them up on all fours and moving 1 alternate leg then arm on opposite sides!
I tapped my hands on the floor in front of my son and he started army crawling then got to proper crawling
My baby girl was motivated to grab things that weren’t hers..like lotion…other people’s diaper bags….water bottles, etc 🤣 We would never hand her these things (obviously because we don’t want her to have them), so that was enough motivation for her to start moving!