SSL and TLS are both encryption methods to ensure your data is safe when visiting websites. Official SSL and TLS support ended years ago, we'll have to rely on community fixes.
Open up the Cydia App, tap Sources at the bottom, tap edit and add the following source:
http://nfzerox.github.io/cydia/
Then navigate to Search, then search for and install the TLSFix package.
Then finally, open cydia.invoxiplaygames.uk/certificates and tap ISRG Root X1 CA (Let's Encrypt)
If you've done everything correctly, you should have much fewer issues connecting to websites :)
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