The 'Mamiii' singer's appearance at the awards show comes the same day as Lletget issued a public apology for amid the allegations.
The 26-year-old superstar wowed in a black Julien x Garbiela gown, which featured cutouts and sheer details throughout. While the dress gave a bit of the cold shoulder, Becky G appeared bubbly per usual, smiling and blowing kisses for the camera while posing for photos on the red carpet.
Becky G also took home a trophy at the annual awards show, earning an award in the Latin Pop/Reggaeton Song Of The Year category for her track with Karol G, "MAMIII."
She posted about the big night on social media, sharing some highlights from the show, writing, "no words but thank you 💙."
The singer's appearance Monday night comes just hours after Lletget released a lengthy statement in which he apologized to his fiancée for what he called a "lapse in judgment," pushing boundaries of lines that "should never be crossed."
"Over the last several weeks, during a moment I regret deeply, a 10-minute lapse in judgment resulted in an extortion plot," the statement shared to his Instagram read, in part. "Since this person did not get what they wanted, it has now become a public social media spectacle filled with more lies than any truth and false posts aimed at the love of my life, the one person I should never take for granted or put at risk."
The soccer star continued, "While this anonymous internet stalker -- who I never met, unlike they claimed -- had an ultimate goal that was not clear, for me, it has been a wake-up call. The loudest alarm of my life."
In an effort to "stop running from his demons," Lletget informed fans that he plans to check himself into a mental wellness program to work on the parts of him that "deeply need healing."
"This past week of chaos & pain has forced me to face consequences of my actions, my fears. & my lapses from the past. have half-heartedly been participating in therapy, knowing I have deeply rooted anger and mental health issues that require the same commitment and treatment that I devote to my physical well-being," the FC Dallas midfielder explained. "If I am to be the man I aspire to be, I have to do better. I have decided to commit myself to a mental wellness program to work on the parts of me that deeply need healing...."
Lletget then directed his apology to Becky G and promised to do "whatever it takes" to earn back her trust and love.
"To Becky, you have been the light of my life, my strength, who has always shown me unconditional love," he said. "Instead of honoring that love every day, I have done the opposite, hurting you and disrespecting the one person that I love more than anything. I am so sorry and know I have to do whatever it takes to earn back the trust and love you deserve."
Lletget's public apology comes just three months after the couple -- who began dating in 2016 -- announced their engagement.
"Our spot forever. 🤍," the 26-year-old singer wrote on Instagram. She paired the caption with three photos from their sunset proposal, with Lletget down on one knee at the edge of the Manhattan Beach pier. He also posted the same photos and caption to his own account.
As for wedding planning, last ET spoke to Becky G, she said she and Lletget aren't in any rush to walk down the aisle or even start planning the whole affair.
"This is a very busy year on the BG agenda," Becky shared. "And my man is in season, officially, so we are in focus, career mode, supporting each other."
The iHeartRadio Music Awards air live from the Dolby Theatre in Los Angeles March 27 on FOX. Check out the full list of winners here!