In 2020 Putin amended the Russian constitution to get rid of term limits but in a really roundabout way.
The old constitution limited a president to two six-year terms total, but when Putin took power he changed it to two terms in a row, allowing him to seek a third and fourth term after taking one term off (during which time he acted as prime minister under his puppet Medvedev). In 2020, the middle of his fourth term, he changed the rules again so that instead of two in a row it went back to the old system of two terms total BUT with the caveat that the rule doesn't apply to former and current presidents; when he runs again in 2024, it'll be as if it were his first term instead of his fifth. He will then run for a second (really sixth) term in 2030, at which point he will probably change the constitution AGAIN so he can run in 2036 and hold power until he dies. Average life expectancy in Russia is 73, which Putin will reach in 2025, but he has some of the best healthcare on the planet so I can see him reaching his 80s or even 90s (Mikhail Gorbachev turned 90 this year, so Putin will probably live to at least 2042).
I expect some more amendments in the coming years, probably tied to the 2024 election; I expect that he will make it so that political parties can no longer choose their own leaders. Instead, all party leaders will be chosen by the cabinet, or will be appointed by a majority vote of the parliament, meaning the majority party gets to pick their own opponents. Putin would install a bunch of his stooges as controlled opposition, making Russia's "elections" even more of a joke than they already are.
Now, the rule changes were "technically" put up to a popular referendum in which the people could vote them up or down, but they passed with near unanimous support from every single constituency except two which the new rules planned to merge into one. Those two results I can believe because they didn't want to merge, but the other 83? There's no way the entire country is that united behind giving Putin more power; that's like if Washington state and Oregon were the only 2 states to vote for Joe Biden, and the other 48 voted for Trump. It was a sham election, no independent international observers, not free or fair.