The only test you take in Texas is a certification test, not a board test. And, the Board of Nursing grants the advanced practice titles, not a certification body such as the AANP.
"Please be aware that Rule 221.2(c)(2) prohibits the use of any titles or credentials that imply that a person is an advanced practice nurse if he/she is not currently authorized to practice as an advanced practice nurse in Texas." page 8 of the link.
Licence comes from the BON, then certification comes from taking the certification exam. You can work in several states as an APRN without taking any tests. However, if applying for a job and others are certified, the employer would more than likely take the certified person over non certified persons.
California, Kansas, and New York do not require a certification exam to work as an APRN. Therefore, you don't need to take any test to work there after graduation. However, as we all know these rules are changing daily, so all of us need to know the rules in our states for working as well as identifying ourselves as advanced practice nurses.