>> 504 Gateway Time-out

Good morning
As the title say I get a 504 Gateway Time-out error when I try to import a 8MB xml file ...
System Info :
php Version 7.0.16
max_execution_time 300
open_basedir /var/www/vhosts/mysite.com/:disappointed:tmp/
memory_limit 3000M
upload_max_filesize 200M
post_max_size 208M

How can I do to solve this ?
I loose it ...