What is “priority based on first application”? How to fill it out?

“Priority based on first application” refers to the priority enjoyed by the applicant when filing a trademark registration application for the same trademark and the designated list of products or services in other countries or regions within six months from the date of the first application in any member country or region of the World Trade Organization or the International Union for the Protection of Industrial Property. When filling out the form, a declaration of the country or region, application time and number of the previous application must be attached, and documents proving the priority claimed must be submitted within the specified time.