@Alexandra
We have an article you can refer to that addressed problems when it comes to Windows 10 activation. For your specific error, our MSFT MVP @andre notes the following:
"Activation servers might be overwhelmed at times because of the volume of upgrades, so give it some time if you get an error message such as (0XC004E003, 0x8007000D, 0x8007232b, or 0x8007007B.) Windows 10 will eventually activate as long as you upgrade using the appropriate method."
For more, refer to the following article:
https://www.groovypost.com/howto/fix-windows-10-product-key-activation/