"I wanted to just post a picture of Charlbi but it's a bit hard," Luke said in his Aug. 31 post. "I just wanted to let you know I see all your messages, all the love and I appreciate it. I really do."
Touching on the outpouring of words he has received, Luke noted, "It's just I can't really reply to them right now but thank you guys."
"I appreciate it," he added. "I love you."
On Aug. 29, the South African star passed away due to "an unexpected sudden illness," her rep confirmed to NBC News. Since the announcement of her passing, no additional details about her death have been made public.
During the span of her career, Charlbi made strides in both television and film. Not only did she appear in the former CW series Black Lightning and the CBS series Elementary, but she also appeared on the upcoming movie Triangle of Sadness—which is set to release in October.
"3 years later!! Against all odds, almost impossible obstacles, they pulled it off!" Luke wrote. "The film is a masterpiece from top to bottom everyone did a spectacularly job getting it done."
The artist added, "I couldn't be more proud of you my love @charlbi143."
Vittorio Zunino Celotto/Getty Images
Charlbi and Luke began dating in June of 2018. In April, Luke shared a look into their romantic proposal, which took place on the streets of Manhattan, New York. He captioned the moment, "This one's dedicated to the love of my life. The girl of my dreams."