Migrants in Mexico have used CBP One app 64 million times to request entry into U.S.

Documents show nearly 450,000 migrants have been allowed into the U.S. under the program.

The Biden administration has tried to establish as the main gateway to the American asylum system at the southern border.

On average, migrants have made just under 5 million appointment requests per month , documents show.

Thousands of migrants from Central America and Venezuela have continued to cross into the U.S. unlawfully each month .

The CBP One system is "providing some order" at the border, but migrants are also giving up waiting for appointments.

Many migrants who enter the country illegally are still released with court notices.