I have a manual solution for your query and it will definitely work.
Step 1: Open your Mozilla Thunderbird application and then click on Address Book option from the menu bar.
Step 2 : After this step, select the address book which you want to be exported from the contact list.
Step 3: In Next Step, Click on Tools option and then choose the Export option.
Step 4 : After choosing Export option, Specify the location and then choose to save the selected address book such as VCF/TXT/LDIF format.
Hope the manual method will help you!
Have a nice day dear!