yes, you'll have to write a cover letter explaining your situation. If your contract letters include your job duties and salary break-ups then a reference letter is not required. However, your contract letters should have mentioned your reporting head and you should include his/her visiting / business card with your request of change to CHC.
but suppose I have already sent my application now u mean I have to write
a cover letter and explain them I left my previous job and country this is
the copy of my contract letter of new job, I will not ask reference letter from
my new employer, otherwise i will
