This is my best guess:

Canadian Income-Tax Treatment of Profits from Disposing of Blockchain Non-Fungible Tokens Canada's Income Tax Act sets out two entirely different tax regimes for business income, on the one hand, and for capital gains, on the other. If you trade NFTs and thereby earn business income, your non-fungible tokens constitute inventory, and your NFT-trading profits are fully taxable. Most marketplaces charge a gas fee for each NFT transaction. As mentioned above, a gas fee is a processing fee for the computing power it takes to validate NFT transactions on the blockchain. If you carry on an NFT-trading business, your transactional gas fees qualify as deductible business expenses.

If your non-fungible token qualifies as capital property because you acquired it for investment purposes, then you include only one-half of the gain when computing your taxable income for the year in which you disposed of that non-fungible token. In this case, gas fees on NFT purchases are capitalized and included in the adjusted cost base (ACB) of that non-fungible token. Gas fees on an NFT sale will offset the proceeds of disposition for that non-fungible token.

https://www.mondaq.com/canada/tax-authorities/1061890/canadian-income-tax-implications-of-buying-selling-blockchain-nfts#:~:text=Canada's%20Income%20Tax%20Act%20sets,trading%20profits%20are%20fully%20taxable.