There are the Francophonie countries, of course, as well as countries whose nationals can learn French more quickly upon arrival in Canada, such as Spain. However, the majority of applications come from North African countries that are former French colonies. These are the largest pools of French-speaking immigrants. Currently, under the Quebec program, which is the equivalent of Express Entry, 30% of applications come from three African countries: Morocco, Algeria and Senegal. Requests from Senegal have increased a lot recently. That's where people are expressing their interest.
However, I'd like to come back to the question of temporary immigration, because it's people in this category who form the recruitment pool for permanent immigration. Temporary immigration doesn't have the same French-language requirements: The employer can find the workers he wants, and simply specify the language required for the job.