no surname on forigen passport what to fill on visit visa form

[Smkuk]

Hi
I am british citizen, and wish to apply my mother visit visa from abroad.
but her foreign passport only given name mentioned no surname, it is blank.

but while i am filling online visit visa form for her it states to give given name and surname
i did wrote given name but left surname blank according to passport but not going further without blank field.

please help me what to do as her name on passport is
given name : kqwe xyz
surname :

what i have to do, any one with the same situation applied recently visit visa with only given name. please guide me or suggest me thanks in advance

[walker]

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