I always inflate with a tube in first.
Remove one bead from the rim and remove the tube leaving the other bead firmly seated.
I then put the tubeless valve in and work round the loose bead encouraging it out of the rim well and onto the rim seat. You’ll not get it all on, but pushing it as far as possible helps with making a seal whilst you pump
remove valve core
inflate with track pump, the tyre usually pops onto the rim reliably. If it doesn’t, I find adding a bit of sealant, sloshing it round then trying to inflate again works – the sealant helps the bead move on the rim and helps create that initial seal.
remove pump and let air out
top up with sealant, reinstall valve core and inflate.
slosh the sealant around a few times every few minutes, then leave wheel in a warm place (in the house ideal)
If air has leaked, I put more in and go for a ride. I find the best way to get the final seal is to go for a ride.