as salam alaikum
it has been reported that the Messenger of Allah, peace be upon him and his family, said:
عليكم باللحم فإنه ينبت اللحم و من ترك اللحم اربعين يوما ساء خلقه
"You should eat meat because it makes meat grows. Whoever abandon eating meat for forty days will get blameworthy traits".
The hadith has been reported from various sources belonging to different Islamic schools with slight variations of wordings.
Although there is no clear prohibition on veganism, from the above-mentioned hadith and other indications from the Qur'an and Sunna we understand that it is not the ideal diet for a Muslim.
With prayers for your success.