"Congrats on 2 years of sobriety to my babe!" Hubbard, who has been engaged to Radke since August 2022, wrote alongside a red heart emoji. "I am so beyond proud of you, your journey, your strength, and your dedication to becoming the best version of yourself."
Hubbard, 36, added: "You inspire so many people! I love you!"
The reality star's post received supportive comments from several other Bravolebrities.
Fellow Summer House star Everett Weston replied, "Congrats Carlito!"
"Yassssss! Happy f---ing birthday @carlradke 👏 so proud of you!" commented VPR's Lala Kent, who is also sober.
Also sharing her post on her Instagram Story, Hubbard called herself a "proud future wifey." She then shared a glimpse into how they celebrated Radke's sobriety anniversary, posting photos from their visit to the Brooklyn Museum to see the Virgil Abloh: "Figures of Speech" exhibit and of their dinner at Vinegar Hill House.
"Today was really nice," she wrote.
Cindy Ord/NBCUniversal/NBCU Photo Bank
Radke, 37, reshared Hubbard's loving tribute and a supportive message from costar Luke Gulbranson. "Some people say they need to make changes in their lives and others actually put it in motion," Gulbranson, 39, wrote on his Instagram Story alongside a photo of the pair.
"Your discipline, love for those who love you and yourself shine every day brother," he said. "Happy two years of sobriety!! Love you amigo!"
Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human interest stories.
Charles Sykes/Bravo Carl Radke
Radke announced his sobriety in 2020, but his struggles with partying and drinking were captured on his hit Bravo series. He's since opened up about reaching an all-time low and how he worked to overcome the problem.
"Watching season 4 back was probably the hardest season to watch back for sure, because it really leans into what I was struggling with is my drinking and my partying," he told Entertainment Tonight in January 2022. "I'm just so proud of the fact that I was able to accept that I knew I had an issue, but that acceptance takes some time."
Hubbard later said that Radke had navigated his sobriety with "strength" and "what seemed like ease."
"The fact that @carlradke has been so open, so vulnerable with his journey, readiness to take accountability, and so dedicated to his own personal growth .. he is inspiring to watch," she previously wrote on Instagram. "I love you baby!"