The Peace Cleric's Emboldening Bond feature can temporary bond creatures together. The effect is as follow
While any bonded creature is within 30 feet of another, the creature can roll a d4 and add the number rolled to an attack roll, an ability check, or a saving throw it makes. Each creature can add the d4 no more than once per turn.
The text specifies that the 1d4 can be added once per turn.
However, can it be rolled more than once?
For example, suppose I have extra attack, miss, and roll 1 on the 1d4. Could I choose not to add the result of the 1d4 for the first attack, and instead roll it again and add it to the second attack?
Best Answer
Using the feature requires adding to your roll
The feature states (emphasis mine):
What the creature is choosing to do is to roll the d4 and add it; these are not separate choices. Numerous features use similar wording and if they had wanted these features to work differently, they would have worded them differently by explicitly stating that you can choose whether to add it after rolling it.
Technically, you declare that you're using the feature before you roll
This can be seen by comparing it to Bardic Inspiration:
Bardic Inspiration explicitly allows you to add it to a roll after the roll is made (though before a result is determined), while Emboldening Bond does not. You must choose to use it before you even make the roll; well before knowing whether the roll itself succeeds or fails.