This is one in a series of Stolpersteine plaques commemorating victims of Nazi extermination.

Inscription:

Hier wohnte
Margot Frank
JB. 1926
Flucht 1933 Holland
Interniert Westerbork
Deportiert 1944
Bergen-Belsen
Ermordet märz 1945

English translation:

Here lived Margot Frank. Born 1926. Fled to Holland in 1933. Interned at Westerbork. Deported in 1944 to the Bergen-Belsen concentration camp. Murdered in March, 1945.

https://www.hmdb.org/m.asp?m=242655