Please follow the instructions for IMM5669 in Guide, "Thanks oulrish,
One more question if i send it via mail, is my husband (principal applicant) need it originally signed or scan will do?
"If you are submitting this form in paper format by mail:
You can fill out the form on your computer (recommended) or fill it out by hand.
If you are filling it out on the computer: In the signature section, type your name and select the date using the date selection tool. Then,
print out the form and sign in writing (provide your original handwritten signature) next to your name in the signature box. If you do not
sign and date the form according to these instructions, it will not be accepted and will be returned to you."