@foliovision Cloudron should create the DKIM records if you're using the DO API for your domains. Cloudron does not delete existing records so if you add something in manually, rest assured it won't get wiped by Cloudron.
https://docs.cloudron.io/email/#dkim
BTW, if you go to your Cloudron dashboard --> Email --> Status --> and click on "Redo DNS Setup", that should add in the required records. It should be listed as a TXT record in DO's DNS.
Example:
TXT cloudron._domainkey "v=DKIM1; t=s; p=TIDfKL7GCS...
