lxml library notorization error : The binary uses an SDK older than the 10.9 SDK

I code-sign with my Mac app, and upload it to notarization service with xcrun altool .

Then I get the notarization error below:
"The binary uses an SDK older than the 10.9 SDK" for the etree.so and objectify.so.

These two so files are from python lxml library (4.6.3, the latest one) in /Library/Python/2.7/site-packages/lxml/ .

I use otool to get the information of the two library, and find its dependency to /usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 1252.50.4).
I also find the library info below:

cmd LC_VERSION_MIN_MACOSX
cmdsize 16
version 10.9
sdk 9.4.1

Due to this is the latest version of lxml, and I have no idea to go forward. Somebody gives me help please.

Thanks