My iPhone SE is locked up and will not work.

What might “locked up” mean exactly?

• Passcode locked? If you forgot your iPhone passcode - Apple Support
• Activation locked? How to remove Activation Lock - Apple Support
• Carrier locked? How to unlock your iPhone for use with a different carrier - Apple Support
• Something else?

If your iPhone, iPad, or iPod touch won't update - Apple Support

Hello ~ Explain exactly what you mean “locked” up? In the meantime take a look here:

If you forgot your iPhone passcode - Apple Support

If your iPhone won't turn on or is frozen - Apple Support

~Katana-San~

Hello again ~ Click on this blue link:

If your iPhone won't turn on or is frozen - Apple Support

~Katana-San~

Hello ~ Go ahead and follow the directions posted by * sberman* as they are best for your situation. I missed the fact that you were in the process of updating your device. Good luck.

~Katana-San~