Here are links to every version (From: https://support.apple.com/en-us/102662 )

• Tahoe 26 (use Software Update)
• Sequoia 15
• Sonoma 14
• Ventura 13
• Monterey 12
• Big Sur 11
• Catalina 10.15
• Mojave 10.14
• High Sierra 10.13

.^.