Yes, as mentioned already, your letter of denial will explain how to appeal. If you have not yet had a phone hearing, that will be your next step. Most hearing officers will require the employer to document that they warned you about performance problems. So, be sure to use that satisfactory performance evaluation as evidence. That will help show they did not warn you about issues. You can also research the unemployment benefits rules at the TWC website.
This information does not create an attorney-client relationship, and the questioner is reminded that s/he should not provide confidential information in a public forum.
Just follow the instructions on the notice that you received. You can appeal the determination, and you will get a telephone hearing before a TWC hearing examiner.