I've been playing the Steam version. I am at a loss on how to assist for other characters at a location, due to lack of rules/tutorials.

Is assistance just having an extra character(s) to lock a glyph on re-rolls? Is that all it is?

Thanks in advance.

Yes, you've pretty much described it in a nutshell. The extra character(s) on the adventure (who would have failed it once already to still be there) can be used to lock an extra glyph after failing a roll. Unlike the boardgame version, though, the assisting character will not lose sanity if the adventure is failed again.

Thanks!