Something like this https://amzn.eu/d/bCmVThi
We have the same bath mat as Steph tagged above! He literally just sits up on it and if he does go into a crawl position he doesn't slip, great for letting them play in the bath too. My baby started using that at 6 months.
@Steph thank you xx
@Chloe thank you xx
We got a non slip bath mat from Amazon and ran shallower baths. Our little one just crawled around and played ☺️