OK I found this post from Jonhannes explaining the workaround with the current version of the software:
Sorry, the 'remote' is removed in 1.0.11 since it was not up-to-date anymore.
As a workaround, to format an sdcard with axoloti:
create an empty patch
add a "script/script2" object, and click the edit button on the script object
put this in the script:
FRESULT err = f_mkfs(0, 0, 0);
if (err == FR_OK) LogTextMessage("format done");
click the "live" button
After several seconds, "format done" appears in the main window.
I will add an object to the factory object library to format cards.