Using Frame Number on Blender 3.6.2 Shading Nodes

Special case

Shader tab

Add -> Input -> Value

Then where the number is, float is set to 0.0 initially, type #frame and it will change the value color to look pink, and you will be able to key off frame number. When you change the slider on the Timeline it will change the pink value, so if on frame 50 will show 50 in value, 100 will show 100, 150 will show 150 etc.

A little confusing that it is a special value. It is also possible to store Frame Number or Seconds from Scene Time Geometry Node and Store Attribute, then pulling the attribute from Attribute on Shader Tab.