Collaborating with DIEM (Bank of things)

Salaam Alajkum,

I have received an collaboration offer from a UK-based company name DIEM. The collaboration is going to be decided.
They are dealing with a marketplace where you list ‘unwanted’ items for others to purchase them. At purchase time you receive instant payment to your VISA debit card provided by them. From their website definition: “DIEM App offers you a free VISA debit card where you can value and cash out
your things including clothes and shoes instantly.” I really appreciate your evaluation of this company from Sharia compliance perspective.

More information
DIEM Website:
DIEM Manifesto: