Consent from landlord

[Hawk04]

Hi everyone,
I need help regarding landlord inviting letter for fiancé visa UK. I found a studio flat , all bills included. But I need a letter from the landlord for my fiancé to stay with me.
Landlord doesn't know what to write.

Can someone please help me.

Thank you,

[CR001]

Do you have a tenancy agreement?

Letter only needs to state that Ms/Mr XY ABC is permitted to reside at Property 123, AB00 2CD, rented by Ms/Mr GHI w.e.f. 1/1/2016 on an Assured Shorthold Tenancy Agreement valid for X months.

Etc. No standard format.