https://www.desidime.com/deals/tomato-300g-2-onion-300g-1-potato-300g-3-cucumber-500g-8-etc?page=2#post_10236066
on iOS, they didn't ask for referral code in sign up process 😭
EDIT :
VU
I was able to use referral code in promo code section at the time of ordering.
Used CRED Pay, paid via SBI Cashback CC (5% cashback) and got Rs. 4 cashback in CRED ... all in all, got items worth Rs. 253 at Rs. 208 (taking into consideration extra Rs. 20 delivery charge).
Location
Available only in Mumbai, Pune, Shrirampur