Talking to other people who work there and reading reviews can help. But the real issue is hierarchical management style is always going to be vulnerable to abuse by bad actors because your managers have near total power over you.

In the private sector the solution is worker’s coops. I’m not sure what it would be called in the nonprofit world but there are likely more democratically run organizations in a similar vein.

Another alternative is finding somewhere with a strong union. Unions can also be toxic in some ways but usually far less so than normal work power dynamics.