Amazon, but it has small cut outs in the sides

Amazon, no side cutouts but design at the collar

Another Amazon but most plus sizes are sold out beyond black

Essentially, Amazon. lol. I just searched “high neck swimsuit”

Shein also has some options if you don’t mind fast fashion

I know I’ve seen some styles like this at Target too but I’m not 100% sure how plus size the sizes go or where you fall on that spectrum, you could always check them out and see.