What can I do to trick my 2.5-year-old toddler into walking longer distances?

Haha... I think there's no trick. You can promise to offer them a treat for covering so and so distance or playfully run after them or make them run after you... but I think all this for a little distance. For more physical activity, if there are kids his/her age then you can make them walk together. Kids are big copycats, they will walk just seeing each other, and you never know, this trick may work for longer distances as well. Else, be happy with whatever little walks your toddler does.

Make it into a game -- whenever I walk with kids and they get tired and want to be carried, I will tell them that if they walk 100 more steps, I will carry the child or reward them with a treat.

lol, why do you want to trick your baby into it? :) you can always play games such that your baby will try to come and catch you, or follow a particular toy and come ahead to get it.

Tell him if he collects 5 stickers you will give him a treat .have a sticker chart. Make it a habit. No candy for walking only sticker. Let him earn his reward. 😊

Give him a sticker as a reward

I run and let my toddler chase me 😂