Mongodb error in php 5

Hi
I try use mongodb library in codeigniter and it is working on localhost on php 7.3
but when i run it on my host with php 5.6,i have error
'Insert of data into MongoDB failed: No suitable servers found (`serverSelectionTryOnce` set): [connection refused calling ismaster on '185.88.179.86:27017']

While it is OK on localhost

I enabled Mongodb extension on host and not problem in extension
I use below library for codeigniter
https://github.com/intekhabrizvi/Codeign...go-library

Please help me