Hi, welcome to OpenStreetMap and many thanks for adding this vegan café.

The cuisine=vegan tag isn't really used any more and has been replaced by diet:vegan=only or diet:vegan=yes (as applicable).

The diet:vegan=* (and corresponding diet:vegetarian=*) tag is used by OpenVegeMap, Veggikarte.de, StreetComplete, etc.

https://wiki.openstreetmap.org/wiki/Key:diet:vegan

Rob