With deep sorrow we announce that
We will gather at the [location, e.g. main entrance of the cemetery]. In lieu of flowers, please consider a donation to [Charity name + IBAN/account details, if desired].
You can fill in the bracketed information as needed. [Last Name, First Name] – A life lived in Rheinhessen
Mainz, [Date] If you'd like, I can also help adapt this for an online memorial page, shorten it for budget-conscious print pricing, or translate it into German.