import demo not enought time

Hi one question please
i try to import demo, but my php 7.1 doesnt let me change upload_max_time…( or something like this) to 3000 but just max to 300. no way to change it even if i aslk for it.
After i tryed, new page come with error, so i go back, and try again… same error…
ok, i decide to go back to site and i sow ny webpage with some demo loaded… i mean was all double, because i tryed twice. this means the demo was imported just fro 300 max_time… was not enough time to import all the demo.
is possible to get the demo in another way? and upload to page?
thansk
i hope you understand what i mean, my english is not so good…
thanks a lot in advance.