Radio buttons allow the user to select one option from a set. You should use radio buttons for optional sets that are mutually exclusive if you think that the user needs to see all available options side-by-side. If it's not necessary to show all options side-by-side, use a spinner instead.
To create each radio button option, create aReference :
RadioButtonin your layout. However, because radio buttons are mutually exclusive, you must group them together inside a
RadioGroup. By grouping them together, the system ensures that only one radio button can be selected at a time.
Android Tutorials and Learning
Firebase Android Tutorials
Create Login Android With Firebase