filling form : do you have an offer of work?

I am currently employed in UK and I do have valid work permit.
I think I can say "yes" for the following question and "choose 1.Employment letter

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Do you have an offer of work?
1 Yes, provide documentary evidence from a prospective employer as to potential role.

0 Contracts 0 Interview invitation
1 Employer letter 0 Job offer

0 No

Am I right ? please help,
cheers,

That is correct. You can mention that you are already working in the UK and provide details.