All people living in France will as usual need to make a declaration of last year’s income this spring.
The only exception is if they have only forms of income already known to the French tax office and can ‘tacitly’ agree to a summary sent to them.
Tacit declaration will not be an option if you had foreign income.
If not in euros, this should, strictly speaking, be converted at Banque de France rates on the day of banking.
The tax authorities have however, tolerated the use of an average rate and have previously said it is acceptable to use an average of the end-of-year rates for the tax year (2021 in this case) and the year before (2020).
Using this, we obtain for major English-speaking nations’ currencies: