My village's post office doesn't have any postcards

I saw posts on instagram on writing post cards to send it to the protest area and to union minister. I wanted to support in the way that I wanted to. So I went to my village's post office and asked for a post card. The person there who was in charge said that the post card is not available? I was flabbergasted and thought I should have done enough research, that post cards should be available somewhere. But I was not wrong. So, now I would like to know what else can I do to support from my side through online.