"online" STCW courses- looks dodgy

I’ve found some training institutes which are listed in the approved USCG course list from NMC. However when you go to their website, they offer online version of courses like BT refresher (PST, PSSR etc.)

My understanding is that some courses aren’t accepted for STCW endorsements because they have a practical demonstration element.

Are there any of the sub-courses within the BT scheme which can be accepted online only? Or do all of them require practical demonstrations of some kind?

All online courses have a a live component. At a minimum, you need to do a final exam live with a proctor or instructor present… You may need to do other parts of the course live also.