your SDK doesn't work 2021 and 2019 Follow
This is the error I get on version 2019 and the 21 is the same but with another version...
"Could not load file or assembly 'Seagull.BarTender.Print, Version=22.214.171.124, Culture=neutral, PublicKeyToken=109ff779a1b4cbc7'. An attempt was made to load a program with an incorrect format."
This is the version of the .dll your install.