You may need to talk to your employer to fix the T4 mistake if it is a mistake. This link has some information regarding to travel benefit, hope it helps: https://www.canada.ca/en/revenue-agency/services/tax/individuals/topics/about-your-tax-return/tax-re...
If turns out later it is a mistake after filed your tax, you can adjust it: https://turbotax.intuit.ca/tips/can-amend-tax-return-7452
Hope it helps
