Could you please share a bit more about your scenario?
Which template app do you want to access?
Further, do you want to access PnP Tenant Templates?
Based on the issue that you mentioned, I suppose that you want to access SharepointPnP.ProvisioningApp.Tenant template, is it true?
If you want to access SharepointPnP.ProvisioningApp.Tenant template of which you are not the owner, you need to be assigned proper permission by your Admin. Please consider ask your admin to assign proper permission to your for using this template.
More details about PnP Tenant Templates, please check the following blog: