KJV: And when we came to Rome, the centurion delivered the prisoners to the captain of the guard: but Paul was suffered to dwell by himself with a soldier that kept him.

NIV: When we got to Rome, Paul was allowed to live by himself, with a soldier to guard him

ESV: And when we came into Rome, Paul was allowed to stay by himself, with the soldier who guarded him.

CSB: When we entered Rome, Paul was allowed to live by himself with the soldier who guarded him.

Internal evidence

The phrase smooths out the narrative, which is a standard indicator that it was added. Why omit a phrase when it makes the passage harder to understand?

External evidence

The evidence against its inclusion is so strong that it is not worth arguing.

UBS gives the omission of the words an A rating.