What things in this sentences are incorrect?

[hoangthi]

Firstly, can I rewrite my question to: What things which are in my sentences are incorrect?
Secondly, can I write this:
"can I use the proof, which shows member (logged in) screen shot of this site, to send by using support button?"
or
'can I use the proof to show screen shot of this site to send by using support button ?'
Thanks

[Barb_D]

Your sentences aren't right, but I'm not sure how to fix them because I'm not sure what you mean to say.

The proof of what? Can I take a screen shot of this site and use the image to prove... what? What does the support button have to do with it?

[hoangthi]

Yes. Thanks for replying.
This is another example, which sentence is correct, and why?
"Can I use a letter, which shows my quotes, to send you"
and
"Can I use a letter to show my quotes to send you?"

[SoothingDave]

Yes. Thanks for replying.
This is another example, which sentence is correct, and why?
"Can I use a letter, which shows my quotes, to send you"
and
"Can I use a letter to show my quotes to send you?"

Neither. It's not clear what you are trying to ask. But the core of your sentence is "Can I use a letter to send you?" and it is missing something.

What do you want to send? How do you want to send it?