where do you get an apple watch adaptor

Do you mean the charging plug?

1. At an Apple Store or online at www.apple.com
2. At a Best Buy Store
3. At a Staples Store
4. Amazon.com

If your signature is correct and you have Apple Watch SE, any USB C Charging plug from 5w or higher will charge your watch.

If you buy a USB C wall charger. It will not support fast charge on AW SE. Only AW7.

My petite 5w USB A iPhone triangular wall charges from 4% to over 80% in 36 minutes which I do not call slow.

Buying 3 USB C female to USB A male adapters on Amazon or eBay cost a fraction of the price of USB C charger and you have then 3 different places in the house of your choice instead of just one

Also very much more Environmental friendly than buying a charger.