This is probably “newly” enforced but if they fly they should automatically receive an I-94 at immigration and I’d they enter by car they need to specify to the agent that that are staying more than 30 days or travelling more than ~50 miles from the border (I’m not sure about the distance) and apply for an I-94 at the border crossing, it’s the same rule for Mexicans, the difference is that the South border has checkpoints where you can’t cross with a visa without an I-94
Many who fly would have already received the required I-94 form, and they don’t have to register if they’ve previously submitted it. Most driving to the U.S. aren’t handed an I-94
This is probably “newly” enforced but if they fly they should automatically receive an I-94 at immigration and I’d they enter by car they need to specify to the agent that that are staying more than 30 days or travelling more than ~50 miles from the border (I’m not sure about the distance) and apply for an I-94 at the border crossing, it’s the same rule for Mexicans, the difference is that the South border has checkpoints where you can’t cross with a visa without an I-94