They are standard dovetails on the underside of the stealth.
Something like this:
https://www.ant-supplies.uk/rifle-bi...il-bipods.html
Although they are out of stock at the moment. Gunpower do their own which is about 80 quid.
Failing that fit a dovetail to weaver adapter block and get a bipod to fit that but it won't look as 'clean'