vps download and upload very slow

I have a vps server that need to be fixed because its very slow. It uses Centos 7 with perl script website now website i adont have any visitor yet

10 vCPU Cores
60 GB RAM
400 GB NVMe
1.6 TB SSD
1gbps


Testing download speed................................................................................
Download: 18.48 Mbit/s
Testing upload speed................................................................................................
Upload: 35.96 Mbit/s

You need to know the problem and fix it