Got scouted via Instagram DM, does anyone know how to check if it's a scam?

Yesterday, I received a casting offer through Instagram DM. But it's not a major agency—it's a mid-sized or rookie label I've never heard of, so honestly, I'm a bit scared and worried .. I heard there are a lot of DM casting scams nowadays... If there are any fellow trainees who know how to filter out if an agency is legit or if I should just ignore it, please share some tips!!