If the cryptoassets received are considered to be readily convertible assets (which is expected to be most likely), the employment income should have been subjected to income tax and national insurance at the time of receipt via PAYE. Where this is the case, it only needs to be reported on the Tax Return if there are other reasons for a Tax Return to be required (e.g. capital gains to report, rental income, self-employment) or if any tax and national insurance met by the employer was not repaid to them.