Item stored in variable with metadata value?

[chikaraa]

Script Version: 2.6-beta2
Minecraft Version: 1.17.1
Full Code:

command /metadatatest:
    trigger:
        # not working part
        set {_diamond} to diamond
        set metadata value "number" of {_diamond} to 6
        send "%metadata value "number" of {_diamond}%"

        # working part
        set metadata value "healer" of player to true
        broadcast "%metadata value "healer" of player%"

Errors on Reload: none
Console Errors: (if applicable) none
Other Useful Info: git-paper-157

Addons using (including versions): skquery 4.1.5, skellett 1.9.11

Have you tried searching the docs? yep
Have you tried searching the Forums? yep
What other methods have you tried to fix it?
fixing it myself by testing a lot of things

Is there any way to make it work?