How to add contact in speed dial function in realme 3i mobile?

Speed Dial Function:-

Bios:-
          Speed dial is not any longer a feature on most Android phones. Now that you simply can add contacts to your mobile , speed dial may be a bit obsolete. However, you'll add contacts to an inventory of favorites. This wikiHow teaches you ways to feature contacts to your favorites list on Android phones.

Instructions:- 
                       

Open the Phone app. 

                                        it's an icon that resembles an old phone receiver. Tap the icon to open the Phone app.

Tap Contacts.
                        it is the third tab at rock bottom of the screen. This displays an inventory of your contacts.

Selection or Addition of contacts:-
                                                            Tap a contact you would like to feature to your favorites. This displays the contact's telephone number and options to contact them.

                                                  If the person you would like to feature to your favorites isn't currently a contact, you'll tap the plus (+) icon within the upper-right corner on Samsung Galaxy phones, or Create new contact at the highest of the contacts list within the Google Phone app to feature a replacement contact on all other Android phone models.
Conclusions

                          How do I unset a speed dial on Android?
Compressive solutions
                                       

                                  Go to the contact and click: More -> Call Setting -> Speed Dial -> click on digit you would like to feature number -> select number, and you're done.