@Wilson403 Likely you have installed the URP Shaders UPM package via Add Package from git URL but installed spine-unity via unitypackage, which is a wrong combination.

See the documentation here, subsection 方法 B - 从git URL添加包, under 重要提示:
https://zh.esotericsoftware.com/spine-unity#%E5%8F%AF%E9%80%89%E7%9A%84UPM%E6%8F%92%E4%BB%B6%E5%8C%85

So either

• a) install both URP Shaders and the code spine-unity runtime via UPM Add package from git URL or
• b) when spine-unity is installed as unitypackage you need to download the URP Shaders UPM zip file, unpack it locally and add e.g. via UPM Add package from disk.. .