my old iphone says iphone is disabled connect to itunes

This applies.

If you forgot your iPhone passcode - Apple Support

After this, before you give away that iPhone:

What to do before you sell, give away, or trade in your iPhone, iPad, or iPod touch - Apple Support

Click here and follow the instructions. Restoring the iPhone requires plugging it into a computer with iTunes installed, or a Mac running Catalina or newer.

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