You can request to connect to residential proxies that have already been online for a certain amount of time by adding ";proxyUptime={period of time}" after your username when you authenticate. For example, to connect to proxies with an uptime of at least one minute, you can add "proxyUptime=1m". To connect to proxies with an uptime of at least 1 day, add "-proxyUptime=1d".
You can select the proxy uptime based on seconds, minutes, hours, or days.
Examples
Unmetered Residential:
curl -x unmetered.residential.proxyrack.net:10000 -U 'username;proxyUptime=30s:password'
Premium Residential:
curl -x premium.residential.proxyrack.net:10000 -U 'username;proxyUptime=30m:password'
Private Unmetered Residential:
curl -x private.residential.proxyrack.net:10000 -U 'username;proxyUptime=12h:password'