If you have a 66 license and did A1 training do need to endorse this category into your license?

No, an A1 training endorsement is not required on a 66 license. A 66 license covers a broader range of activities than an A1 category would. The A1 training is likely already implicitly covered within the scope of your 66 license. You would only need an endorsement if the specific regulations in your jurisdiction require it for certain tasks or operations, but this is uncommon.