How do I unlock a disabled iPhone 4 without losing data?

According to Apple, iCloud backup and restore currently requires iOS 10 or higher, although Wikipedia authors seem to think that iCloud backup once worked on versions of iOS as old as iOS 5.

System requirements for iCloud - Apple Support

An iPhone 4 cannot update to iOS 8 or higher, so it seems unlikely that there are any iCloud backups to restore. The OP may want to check to see if there are any local backups of the iPhone, stored on a Mac with the help of iTunes.

Yes, you will have to reset it.

Click on the link for instructions on how to reset your passcode using a computer.

If you forgot your iPhone passcode or your iPhone is disabled - Apple Support

ZoeDodson wrote:

So I recently found my old iPhone 4 but it’s disabled, when I connected to iTunes it says I need to put the passcode to use it with iTunes. Does this mean I’ll just have to reset it and lose all the things on the phone?

To recover data from a broken phone, first check for cloud backups (like Google Drive or iCloud) and download them to a new phone. If backups aren't available, you can try using data recovery software or connecting the phone to a computer with a USB OTG adapter to access the files. If you are trying to use the iPhone 4 for your phone then, it won’t work very well and you should look at getting a new phone.If you are concerned about prices you can get a iPhone SE 3rd gen for about $150, https://www.walmart.com/ip/Restored-Apple-iPhone-SE-3rd-Gen-Carrier-Unlocked-A2595-64GB-Red-Refurbished/2407818009?wmlspartner=wlpa&selectedSellerId=101018093&selectedOfferId=8CE6CF28F6EC4133BD4183FD19A9D676&conditionGroupCode=2&gclsrc=aw.ds&&adid=222222222272407818009_101018093_178094884233_18606250977&wl0=&wl1=g&wl2=t&wl3=739727031100&wl4=pla-2225775695509&wl5=9030244&wl6=&wl7=&wl8=&wl9=pla&wl10=244651298&wl11=online&wl12=2407818009_101018093&veh=sem&gad_source=1&gbraid=0AAAAADmfBIrDxX1aQsvdAaMVvDC95J7Ap&gclid=EAIaIQobChMI1Pyf8eXJjAMVth9ECB2cWgeGEAQYASABEgJ5CvD_BwE or a around $180 iPhone 11, https://www.walmart.com/ip/Restored-Apple-iPhone-11-64GB-Verizon-GSM-Unlocked-T-Mobile-AT-T-4G-LTE-Smartphone-Black-Refurbished/338377417?conditionGroupCode=2. I hope this helps 😀!

you can try using data recovery software or connecting the phone to a computer with a USB OTG adapter to access the files.

Neither of those suggestions will work if the phone is locked.