I ran the PSDK but no buttons were bound to the DA2?

The function of the binding button is to bind the DJI official kit (only SkyportV2 and X-Port need to be bound). First, you need to confirm whether the model you are using is M300 M350. Only these two models need to be bound. Other models do not need to be bound. Secondly, confirm whether the port running PSDK is the gimbal port. Only the gimbal port can connect these two kits.

The gimbal port usually has a gimbal bracket. In the following position, there will be an upper gimbal bracket, a lower single gimbal bracket, or a lower dual gimbal bracket.

Binding can follow: https://developer.dji.com/doc/payload-sdk-tutorial/cn/quick-start/run-sample-code.html#%E5%BA%94%E7%94%A8%E7%BB%91%E5%AE%9A-%E4%BD%BF%E7%94%A8-xport-%E6%88%96%E8%80%85-skyport-v2