how to send Steam trade offer to bot without using steam official website

[Syed]

My problem is when i send any offer from the steam official site it worked, but I want  to create a site like skin port, I created a bot who accept any offer and receive any offer.

I want any user who are register on my platform they can send trade offer to our bot with using our native platform like skin port 

https://skinport.com/

[Syed]

Can any one help me? I have a bot who can accept and send any offers to any steam user (term & condition apply). but the problem is , I want, when user login into our platform  we fetch user inventory using steam api, I want user send offer to user bot using our platform.

please help, how can I implement these flow or suggest better flow, 

[Dr. McKay]

No, that's not possible.