Reckless abandonment says:
From the 6th level, when you use Reckless Attack while raging, you also gain temporary hit points
Reckless attack says:
From the 2nd level, you can dismiss any worry
for the defense to attack with fierce desperation. When you do your
first attack in your turnyou may decide to attack imprudently. Make
So gives you an edge on melee weapon attack jets by using force
during this round, but the attack rolls against you have the advantage until that
your next turn.
Since the rash attack only triggers when you make your first attack, it can only be used once per turn. your turn, unlike Sneak Attack). Therefore, you can only benefit from indiscriminate abandonment once per turn.
In addition, as Purple Monkey points out, temporary HP batteries from multiple sources do not stack. Even if you could Use Reckless Abandonment Many Times During Your Turn, You Only Have 5 Temp HP: How Does Armor of Agathys Interact With Obtaining Temporary Hit Points?