End of month I will fly into Dubai with Qatar Airways and 4 days later out of Sharjah again with Qatar Airways.

I travel on a passport which do not require a visa, however my wife travels on a Thai passport. I contacted Qatar Airways and the Ritz-Carlton in Dubai if they are able to support the visa application, however both of them mention that they don’t support any visa application. I am a bit puzzled where I could apply for a single-entry tourist visa. Any help is much appreciated. Thank you!