When 'to' is a preposition rather than part of the to-infinitive, an ing-form (gerund) may be possible.
I look forward to seeing you.
I am used to driving in Prague.
I prefer drivimg to going by coach. I went from eating too much to drinking too much.
Note that in these examples,a to-infinitive is not possible, but a noun is, for example:
I look forward to the party.
I am used to Prague traffic.
I prefer cars to coaches. I went from over-indulgence in food to alcoholism.
In your example, neither a gerund nor a noun is possible:
I'm here to applying for the job.X I am here to the job/application.X