Superdrug Semi-Permanent Hair Dye help needed.

[Needmorelego]

My daughter wants to dye her hair and we bought this from Superdrug.
The instructions are too vague for me.
Am I meant to use the whole bottle (125 mls)?
There's reference to "do not use metal bowl for mixing" but there's nothing in the instructions about mixing. One review also mentions mixing so I am totally baffled.
Help please.
Thanks very much 🙂

It can be used alone or added to a conditioner for maintaining a red colour.

Bear in mind, even though it's semi-permanent, it will stain with it being red - particularly if she has light hair.

Yes

Thanks @Wiii and @hdbs17 . We watched a You Tube video and gave it a go.
Hopefully it will be red. Or at least red -ish.
😬

Well we ended up with kind of red - ish highlights.
She seems happy enough 🤣