How to bring this to alpha channel?

[charlie38684979ugbr]

I am trying to create a color map for use with a rendering software. My understanding is I need to add the cutout geometry to an Alpha Channel per the instructions here.

[D Fosse]

If it's just getting it into the alpha channel - simply copy/ and paste it with the alpha channel targeted. To target the alpha channel, shift-click it.

[charlie38684979ugbr]

I am not seeing anything get pasted when I do this

Steps:

- Open PNG file 

- select :

- ctrl-c

- shift click alpha channel:

- ctrl-v

nothing is visible

[D Fosse]

Ctrl+A (Select All)?