key in
phrasal verb.to type information into a computer or device using a keyboard.
phrasal verb.to enter data or text into an electronic system via a keyboard; transitive phrasal verb with the object following the particle directly.
“Please key in your password to access the account.”
“The customer service agent asked the user to key in their order number for verification.”
“As the deadline approached, the programmer worked tirelessly to key in the final lines of code before the system went live.”
takes a direct object — the information being entered into the device.
compare with 'type in' (near-synonym) but note 'key in' specifically implies keyboard input, while 'type' can sometimes mean handwriting.
'into' is incorrect here; the particle 'in' directly precedes the object without prepositions.