Question about patching holes inside the oven

[Anskydude]

Hello-I'm new to these forums and glad I discovered they exist. I've had this pre-fabbed brick oven (similar to the pre-made Forno Bravo ovens) for a year and some minor holes have developed in the mortar in between the bricks inside the oven. My question is: what's the best way and material (preferably something that's pre-mixed and for sale at a Lowe's or Home Depot) to fill in these gaps? I purchased a tube of Rutland Fireplace Mortar but am a little concerned if this is safe to use inside the oven because it's not really food-safe and will theoretically come into contact with my pizza. Thanks in advance for your input.

[fox]

That is a tiny issue compared to many!
The only problem small fissures like that would cause is cement partials falling on your food.
There are many high temperature repair products available usually based on clay or cement, I would guess the one you linked is a clay based and would be perfectly safe.
However those sort of repairs do tend to show up once filled, be careful not to get any on the surrounding bricks if you want it to look neat.