Thank you for your prompt response @geeksville but precisely I only find it in the 868 or 915 MHz versions 
By example : https://fr.aliexpress.com/item/4001287221970.html
I would like to experiment and compare links between 433 and 868 MHz (in Europe)
ps : I favored the urls given here: https://meshtastic.discourse.group/t/retailers-for-ttgo-board/178/3 but even elsewhere nothing