How does one 'put themselves out there'?

I would ignore it if it were only one or two of my buddies telling me this but I am getting told this by a couple of my friends that as a guy, I'm supposed to be 'putting myself out there'. I didn't express any willingness to be going out and looking for relationships but my friends tell me that they think I'm putting extra efforts to hold myself back (I don't know how). I'm good at speaking whenever it is needed, I just don't flirt or gossip around.

I don't expect any miracles or some girl coming out to approach me but what's something a guy should be doing for putting himself out there? Is it a must... something guys should be doing or am I missing out on something?

How does one 'put themselves out there'?
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