Take the following steps:
- Go to www.ultimate-guitar.com on desktop and click on the yellow "Submit" button which you can find in top right corner of any page.
- Write the tab or upload your GP/Power Tab file.
- Then just click "Save as personal" button.
- You'll find your Personal tab in "My Tabs" section.
At the moment it's possible to create Personal tabs only on desktop version of www.ultimate-guitar.com however you'll be able to view Personal tabs on all platforms in August, 2017.
Note: if you don't have an Ultimate Guitar account, it's worth registering one before you start creating the tab.