Validity of h1 approved in 2015 november

Hallo ,

I have a H1 approved in November of 2015 while in Australia and never went to stamping, Now in EU ( Prague) and wondering if its still valid and I can go for stamping .

This is my second H1( I used up the 6 years on the first H1 in 2015 ).

Any one have any experience on H1 stamping in Prague, CZ

Any pointers will be great help .