Ad: This forum contains affiliate links to products on Amazon and eBay. More information in Terms and rules
A good shot, possibly a G-1.
Eng
View attachment 816514
IMHO the seller made a mistake: theoretically there could not be a "Ergänzungsstaffel 45". The "Staffeln" were mostly up to 13-14 with some exceptions, but never 45.
The emblem we see is the one of Ergänzungs-Jagdgruppe Ost:
View attachment 816512
View attachment 816513
The latter had 4 Staffeln - see here. So it's probably Ergänzungsstaffel 4.
It's interesting that the soldier we see is in fact a sailor/seaman (Matrose) from the German Kriegsmarine.
Ergänzungs-Jagdgruppe Ost was initially located in St. Jean d'Angely, which is a French commune on the ocean so it makes sense to see a sailor there.