How to add SPF TXT record which has the same record name with other TXT record already exist

It is possible to register multiple TXT record values.
Points to note when setting up.

• Enclose records (values) in double quotation marks (") to identify them.
• Each record (value) should be entered on a new line.

This means that the value of the TXT record should be set as follows.

"v=spf1 include:amazonses.com ~all"
"test-ABCDEFGHIJK"

It would also be a good idea to perform an SPF Record Check after the settings are made.
https://mxtoolbox.com/spf.aspx