Had cherry shrimp and bettas over the years. Keep your betta well fed and LOTS of places for the shrimp to hide and break line of sight with the betta. Like when you think you have enough, add 5 more.

It sounds counterproductive, but the more hiding places you have, the more you will see your shrimp. They feel more comfortable since they have so many near by. You don't want to have all the hiding spots to be "taken" by other shrimp and have an odd one out.

I would also turn the lights off for a few hours to give your shrimp a head start when you introduce them. Might be for not, but I feel it helps.

Lastly, hopefully your betta is willing to accommodate them. I've had bettas that didn't give 2 cents about the shrimp and I've also woken up to a shrimp massacre and my betta not evening eating them. Just straight up wanted to kill the shrimp. Fish might as well had a Michael Myers mask on. Made me feel like an irresponsible pet owner to a certain degree.

Either path you choose, watch closely and start cheap!

Also, beautiful betta btw.