[Terretta]

You can only estimate what's known.

If the problem is in fact known, your estimate will be the time to pull in a library from GitHub. If it's not to pull in a library, you're into unknowns.

Asking to estimate may work in aggregate if your 'gut' is good at assessing the amount of unknown your devs' face (e.g., 2x as much unknown work - multiply estimate by 3), but not in the specific. The specific amount of unknowns in a given task are unknown.

To translate a requirement into code will take exactly as long as it takes to discover and bridge the unknowns. You can't do anything about that, other than (a) change the requirement, or (b) change how much is known by the developer.