Dear Arif,

There should be only one corresponding author (ideally the last author), however, equal senior authorship can be shared between 2-3 based on the contribution to the study( supervision, study design, drafting and funding). Best wishes, Emran

There should be no more than two corresponding authors. The corresponding author is usually the first or last author, and if there are two corresponding authors, then one should be the first and the other should be the last author on the manuscript.