For static maps, we need to always display an attribution line for Wikimedia and OpenStreetMap (OSM), no matter the size of the map.
As referenced here, for OSM, we need the following:
Our requested attribution is "© OpenStreetMap contributors". Because OpenStreetMap is its contributors, you may omit the word "contributors" if space is limited.
For static maps - the minimum attribution to be displayed is:
and the link will be attached to "Wikimedia" in the attribution line for all static maps: https://wikimediafoundation.org/wiki/Maps_Terms_of_Use