Cantrips generally get more powerful as you progress in your spellcasting class.
The Spell Sniper feat allows casting a cantrip.
If you pick a Spell Sniper cantrip from another class will the damage increase? E.g. A level 6 Fighter takes the Spell Sniper feat and chooses Produce Flame. Would the damage be 1d8 or 2d8?
Cantrips increase with your character level, which is independent of how many levels you have in spellcaster classes. If you are a multiclassed level 2 wizard, level 2 druid and level 2 cleric, you are a level 6 character for the purposes of Cantrip damage. The source of the Cantrip (spellcasting class, race, feat, etc) has no impact on this.
Cantrips
If a character has levels in more than one class, do the character’s cantrips scale with character level or with the level in a spellcasting class? Cantrips scale with character level. For example, a barbarian 2 / cleric 3 casts sacred flame as a 5th-level character. (Sage Advice Compendium V_2.0; page 11)
