Impossible to flash TWRP

Hello, I am trying to install /e/ on my smartphone, but i am actually stuck.

I followed different thread but couldn't find response.
I managed to activate fastboot, and unlocked my phone; USB debogage is activated and EOM too.
My phone is actually on factory version - but i activated USB / EOM debogage again and i checked phone is unlocked.

I am trying to flash TRWP before flashing /e/ . But i can't flash TRWP. I got an error : ANDROID_PRODUCT_OUT not set
I read somewhere i need to...

Read more