*Urgent please* -Fee waiver code where to fill in?

[VW1]

My wife has applied for FLM R Visa extension and been granted a fee waiver code finally. Her online application has been completed and she’s uploaded her documents to UKVI.
We need to urgently know where you enter this code, the online application looks completed and there’s no where you can enter it now? Repeated attempts to contact fhrufwcocqueries@homeoffice.gov.uk ApplyOnlineE-Support@homeoffice.gov.uk FHR9DestitutionQueries@homeoffice.gov.uk has been utterly useless and unhelpful.

Please can someone help as I have 1 day or so left before the code expires !?

Thanks.

[VW1]

Thanks for all the replies

Thought I'd update anyone who has the same issue I contacted the visa section of gov.uk on 0800 790 6268 and was advised to restart the Visa application and at the end it did eventually let me enter the code. Now I have to do the whole uploading of documents payslips, bank statements all over again