Open the Phone app
Open Recents or the call log
Tap the info icon (i) next to the number
Select Block Contact / Block Caller
Confirm Block
Open the Phone app
Go to Contacts
Select the contact you want to block
Tap Block Contact / Block this caller
Confirm Block
Open Settings
Tap Phone
Tap Blocked Contacts
Add a new blocked number
Enter the number or select it from contacts
Tap Block
Open Settings
Tap Messages
Tap Spam Protection / Blocked Contacts (name may vary)
Add the number to blocked lists or spam blockers
Confirm
Open the Messages app
Open the conversation with the number
Tap the contact name or info icon
Select Block / Block & Report Spam
Confirm Block
Open the app store
Install a call/text blocking app
Open the app
Grant required permissions
Add the number to the block list
Enable blocking and notifications as prompted