Same as what Anne has said. I've also been recommended to attend postnatal pilates
Have you tried the app ‘Squeezy’? It guides you how to do your pelvic floor exercises properly & reminds you!
I'd definitely recommend the physio too, after my first I ended up needing a stimulator to help strengthen the muscles before me doing exercises that could then help more. Plus she gave me other exercises to help.
If you are able to see a women's health physio, this would be a great place to start for a functional assessment. Lots of movement in our pelvic space during pregnancy and postpartum. They will be able to guide you with rehab exercises specific to what's happening in your body :)