There are many examples of countries that have managed to absorb immigrants relatively successfully. But France has one of the worst records.
America has 65 million Mexicans and 47 million blacks. There are problems but they’re not burning the country down. Americans bend over backwards to accommodate minorities. There are huge numbers of blacks and Mexicans in positions of power and their issues are addressed. Muslims in America are treated quite well.
Canada has millions of immigrants and they also live peacefully. The worst place in Canada for Muslims is Quebec, which gets its ideas from France.
In France they treat immigrants like dirt. They regularly insult Islam and even third or fourth generation Muslims feel like a hated minority. Same with blacks. Either don’t let them in but, if you do, then treat them well so that they integrate.