There has been an important change regarding taking the JLPT in Japan.
This year, only individuals who have a residence status in Japan for more than three months are eligible to take the JLPT.
When applying, you will need to provide your Residence Card number and its expiration date.

In other words, people who are staying in Japan for three months or less, such as tourists, cannot take the exam.
Even if you are planning to come to Japan soon, you cannot apply for the JLPT unless you already have a Residence Card at the time of application.
Please check the reference link below for more details.

Reference Link:
JEES JLPT