This solution is working well. Nevertheless, certificates have dealine, so if i don't want to download sketch each time a certificate is out of date, I think it would be better to Upload SSL root certificates in Arduino IDE. And i don't success to done it on my Arduino R4 wifi as it fails each time i try to do it. My firmware is up to date and i use Arduino IDE 2.3.4. Does everybody have an idea on how to upload SSL rott certificate on that board ? Many thanks for all contributers