Long story short…nope. As stated in the Plasmic documentation:
Supabase allows you to set Row Level Security (RLS) policies on tables, and it defaults to on. However, since Plasmic currently connects to Supabase with a direct connection, Plasmic is unable to use auth features and most RLS features. To query a table, you’ll need to make sure the table has RLS turned off or has a permissive RLS policy that enables read access for all users.
We have been talking about this in this post. If you strictly need RLS policies, I guess you will have to implement your own requests through the React library…