What is the business code for mobile app development on Schedule C?

I can only find code 541510 using 'Code lookup' in turbotax, but I really don't think 541510 is a valid NAICS code (it even doesn't list on NAICS official website)

 

Will 511210 (software publisher) work for mobile app development? but i cannot find this code in the TT

'Code lookup'

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