How to get out of being asked to be a secretary?

I work for a fintech company where things are going pretty downhill but due to the market right now, I'm not comfortable resigning unless I have something lined up.

Most VPs have resigned including my boss and the company feels very sexist.

I am a business development manager and manage an account and work with a solution engineer. In meetings with clients, he will get assigned action items and he asks me to "take notes and remind him of the action items" so he remembers what to do.

I am not a secretary. I am not an EA. It's not my job to manage his tasks. How do I change this?

I make 200k so apart of me is like, do I just take notes because I only have to deal with this for a bit longer?

they keep taking ownership away from me even after I've exceeded my targets and client goals and treat me poorly but I can't leave.

Push back and set some boundaries, this person is being sexist and offloading their work onto you. I am unfortunately in a similar situation with my boss and it has gotten out of control because I never pushed back (I was told it would be temporary until they found someone permanent and stupidly believed them). Now the market is horrible and I'm stuck doing an EA job when I have an advanced degree. Remind this person what your role is and calmly tell them that EA work is outside the scope of your job and not something you have the capacity to provide for them. And start looking ASAP.
Send him reminders to give you a raise for doing his job as well as yours.
I would consider approaching him before the next meeting and say "I've noticed that in meetings you often ask me to take notes and remind you of your responsibilities. I'm happy to serve as a sounding board and thought partner for you, but taking notes and keeping track of your responsibilities isn't in the scope of my job as a business development manager and more importantly, it doesn't seem like an efficient way to do things. Do you think we need to see if we can get some administrative help for this client?"
The mature way to handle this would be to have an upfront conversation with him where you assume he's coming from place of genuine misunderstanding. You could say something like, "I think there may be some confusion about our roles. I've noticed you often ask me to take notes in meetings and follow up with you about action items. My role is actually to XYZ, so I won't be able to do that for you."If that doesn't work or you don't trust your coworker to handle that conversation maturely, you could have the conversation with his manager instead.But...what would happen if you just didn't do what he asked? If it's truly not your job, what's the worst that happens: He complains that you're...not doing something that you're not supposed to do?
You should have a discussion with the solution engineer's manager and himself, and refuse to do secretarial work going forward.They are taking away ownership from you because you have exceeded your targets and client goals. They are insecure. Your goal right now is to know that about yourself and not spend any more energy on this company. You can, however, try to see how you can deal with insecure people as an exercise before you land another position.