This comes straight from the mouth of the Lord about repentance leading to salvation like the whole bible shows.
For thus the Lord God, the Holy One of Israel, has said, in repentance and rest you will be saved, in quietness and trust is your strength. But you were not willing. (Isaiah 30:15)
And an extra 2 witnesses here.
“When they heard these things they became silent; and they glorified God, saying, “Then God has also granted to the Gentiles repentance to life.” (Acts 11:18)
“For godly sorrow produces repentance leading to salvation, not to be regretted; but the sorrow of the world produces death.” (2 Corinthians 7:10)
As we can see; Repentance leads to life/salvation.
What is repenting? Forsaking sin(a total change of mind to sin). Isaiah 55 :7 ‘ Let the wicked forsake his way , and the unrighteous man his thoughts and let him return unto the Lord , and He will have mercy upon him, and to our God , for He will abundantly pardon.
As Proverbs states “Those who confess and forsake will find mercy”.