Hi Harvinder, just a quick footnote,
you may want to double check your outbound rules and possibly add a few more in to see if this can help
for reference, when I setup a 3cx instance normally I put in place a series of rules for different dial scenarios, so for example
ie, my default setting is first for a 10-digit dial rule, which covers calls in north america such as
abc-def-ghij
then a catch-all for outbound international, basically anything with prefix 011 and then 'whatever else' as call digit length
then a simple rule for permit skip the local area code if people want to avoid dial that (ie, local area code for me is 902 so if client wants to reach 902-123-4567 they may dial simply 123-4567 and the system will auto-complete / assume 902 is a given
then an 11-digit dialer to get north america 'long distance' that client prefixes with a one
and the system default rule, any 3-digit dial is for internal use only and does not route up to the SIP trunk
ie, maybe your problem is that your rules are not suitably matching what you are trying to do
and hence they fail
note in my screenshot above all my "Route1" are going out to a single SIP trunk carrier I have set on my 3cx host
but I've obscured the name in my snip. but it is there and visible

just hidden in this thread / obscured.
you can optionally route to different sip trunks etc if you prefer one carrier over another for international vs 'local' etc
but that is 'icing'
and of course could designate 'failback' sip trunk route (ie, if first trunk is down use second trunk to route outbound, etc)
hope this helps
Tim