The lawsuit filed Tuesday is the latest legal salvo attacking various aspects of the administration’s plan to manage migration in the aftermath of the end of a key pandemic-era immigration regulation called Title 42.

In the lawsuit, Texas argues that the asylum rule encourages the use of a cellphone app — called CBP One — for migrants who don’t have proper documentation to make an appointments to come to a port of entry and seek entry into the United States.

Texas argues the Biden administration is essentially encouraging people to come to the U.S. even though they don’t have legal basis to stay.

“The Biden Administration deliberately conceived of this phone app with the goal of illegally pre-approving more foreign aliens to enter the country and go where they please once they arrive,” said Texas Attorney General Ken Paxton in a news release.

The complaint was filed in the Western District of Texas.

While the lawsuit focuses on the phone app, it seeks to throw out the entire asylum rule, called the Circumvention of Lawful Pathways. The rule went into effect when Title 42 expired May 11. The rule makes it extremely difficult for migrants who travel to the southern border to get asylum if they don’t first seek protection in a country they passed through before reaching the U.S. or if they don’t apply online through the app.

Use of the app is a core part of the administration’s plans to create a more orderly system at the border where migrants set up appointments ahead of time, but when the app was rolled out in January it was criticized for technological problems and because demand has far outstripped available spaces. Migrants can make appointments for specific ports of entry — five of which are in Texas.

Texas argues that according to federal law, people entering the country illegally — with rare exceptions — should be expelled but that the app doesn’t verify whether the migrants seeking appointments would qualify for exceptions. Therefore, the state argues, the Biden administration’s use of the app essentially encourages people to come to the U.S. even if they don’t qualify. Texas also argues that it has to pay the financial burden of migrants coming to the U.S. through things like health care or education.

The new asylum rule has also been attacked by rights groups who argue the U.S. has an obligation to offer asylum to those in desperate need. They’re suing to have the rule thrown out as well. Texas is also part of another lawsuit accusing the administration of overstepping its authority by allowing as many as 360,000 people a year from Cuba, Haiti, Nicaragua and Venezuela to enter the U.S. under its humanitarian parole authority.