How can I submit my 1098 form If my Financial institution, (RoundPoint Mortgage Servicing Corporation) isn't listed ?

Choose "I'll type it in myself" and enter the information by keying it in  by hand.

Are you trying to import your 1098 (Mortgage Interest)?  

Our new mortgage company will not show up when I type it in 

If you typed the lender's name on the import screen and it's not listed, then click "Change how I enter my form".  You can either upload your copy of Form 1098 from your computer, take a photo of the paper form with your phone, or click "Type it in myself". In many cases, typing it in yourself may be the quickest option.

See this TurboTax Help article for more information.