On Android system you can use Termux (No root required):

1. Navigate in Firefox to URL:
   file:///data/data/org.mozilla.firefox/files/mozilla/
2. Choose the link of ***.default folder of your profile
3. Choose the sessionstore.js file
4. Copy contet of this file and save it in sessionstore.js file on local storage
5. Run the command in Termux:

to output your tabs urls, or:  

cat ~/storage/shared/sessionstore.js | sed -n 's@{\"url\":\"@&\n@g; s@\",\"title\"@\n@gp' | sed '/^[:{]\"/d' > ~/storage/shared/sessionstore.txt
to save your tabs urls in file sessionstore.txt on your local storage.

On Android system you can use Termux (No root required):

1. Navigate in Firefox to URL: file:///data/data/org.mozilla.firefox/files/mozilla/

2. Choose the link of ***.default folder of your profile

3. Choose the sessionstore.js file

4. Copy content of this file and save it in sessionstore.js file on local storage

5. Run the command in Termux to output your tabs urls:

    cat ~/storage/shared/sessionstore.js | sed -n 's@{\"url\":\"@&\n@g; s@\",\"title\"@\n@gp' | sed '/^[:{]\"/d'
   

Or, this command to save your tabs urls in file sessionstore.txt on your local storage:

    cat ~/storage/shared/sessionstore.js | sed -n 's@{\"url\":\"@&\n@g; s@\",\"title\"@\n@gp' | sed '/^[:{]\"/d' > ~/storage/shared/sessionstore.txt