It's in Webnovel, however the free chapters only goes until chap 40, beyond that is locked and it can be unlocked by using coins or fast pass (you can get 3 fast pass daily by logging in and voting while you buy the coins with money). There are other unofficial sites where you can read it too which I'll link here....
Wuxia World: https://wuxiaworld.site/novel/only-i-level-up-novel-solo-leveling-completed/
Light Novel Pub: https://www.lightnovelpub.com/novel/i-alone-level-up-solo-leveling-17031322
These are the ones I use (mostly light novel pub tho ^^;) please read in Webnovel if you can (⌒▽⌒)
Uwu thank you my savior
no problem ^^
Anyone knows where can i read LN of this?