terraform var simple syntax help?

Please see below a small syntax help guidance needed? The var myhostname is "xyz-123" and would like to value = "${digitalocean_droplet.xyz-123.ipv4_address} How above can I replace "xyz-123" with var myhostname ? (perhaps we can do this quick on screen share and 5 stars?) SINCERELY WOULD BE NICE TO MEET YOU PLEASE My funds are low but will pay quick and leave 5 stars. Please give your best possible for your bid ? (something reasonable?) Please note there is hope we can mutually complete this task; we can leave each other nice comments and 5 stars for each? Look at feedback on my profile, feedback I left for many others. Here is the project: ANY THOUGHTS ? Please note project is due in TWO HOURS as this projects deadline, as this is needed if we can get some done - then we can talk about next steps and 5 stars and another job also. If this is a good one and we are "successful"; would need a couple others setup, but will handle one at a time? Can you do this for something reasonable in a couple hours? thoughts ?