Contact the organizer of the training and inform them of the food allergy. It’s the same as accommodating people with mobility disabilities, etc.

What about a cup a soup or u can get allergy pot noodles here... I use ice packs, buy hummous and bread with tomato and this usually lasts. To be honest I also have to eat junk like crisps ( chips)? When I’m away as it’s limited depends where u are

What about a home made trail mix that doesn't contain your food allergens, fruit, and any vegetable that might keep well without refrigeration?

My husband or other friend that knows all about my food allergies typically goes with me when I travel and makes sure I have the foods I need by shopping for them while I am at an event. My disabilities make shopping and traveling alone impossible.