i want to transfer all my contacts number to memory card (SD card)

For contacts stored in iCloud see here ➜ Import or export a vCard in Contacts on iCloud.com - Apple Support

No way to do that on an iPhone directly.

iPhones have no Sd card slot, and have no wya to transfer contacts to an SD card.

Contacts on an iPhone are stored either on iCloud or some other e-mail service. You should be able to export the contacts from the email service website as a CSV file or other format and then store on a SD card.

for iCloud see here