Right to cooperate by e-mail because of mental health?

I am currently on sick leave, I have signed a settlement agreement with my employer (released from duty 1er june / end of contract end september).
Yesterday they reached out to instruct me to meet them because they think there is a breach in my contract.
I said that due to my mental health I couldn't meet them but willing to cooperate but by email.
I am in my right to only have communication by email ?