For Xcode 11 and above, Application loader is a separated app called Transporter
To update transporter components write this
/Applications/Transporter.app/Contents/itms/bin/iTMSTransporter
Note: If you encountered error like this
...
.......
<main> INFO: indexing file: /Users/<YOUR USER>/Library/Caches/com.apple.amp.itmstransporter/obr/2.0.0/org.apache.tika.core-1.18.0.jar
<main> INFO: indexing file: /Users/<YOUR USER>/Library/Caches/com.apple.amp.itmstransporter/obr/2.0.0/com.apple.transporter.aspera-linux-x64-3.9.1.2019-07-18-1737-EST.jar
<main> INFO: indexing file: /Users/<YOUR USER>/Library/Caches/com.apple.amp.itmstransporter/obr/2.0.0/com.fasterxml.jackson.dataformat.jackson-dataformat-xml-2.9.6.jar
<main> INFO: Update check complete.
<main> ERROR: unsatisfied requirement: com.apple.transporter.mediatoolkit
<main> ERROR: (&(package=com.apple.its.epubcheck)(version>=4.3.0)(!(version>=5.0.0)))
<main> ERROR: unsatisfied requirement: com.apple.transporter.aspera-linux-x64
<main> ERROR: (&(osgi.native.osname~=Linux)(osgi.native.processor~=x86-64))
<main> ERROR: could not find the service with interface (com.apple.transporter.osgi.TransporterService)
write this command
cd ~
mv .itmstransporter/ .old_itmstransporter/
Then repeat the first command
References: One Two