Hi @kankuraon.
Welcome and thank you for posting here in the Roku Community!
We appreciate you for reaching us regarding your query and we're here to assist you with this.
May we know what model type is your VHS player? Usually, VHS players are connected through an auxiliary cord.
Keep us posted on what you find out and we'd be more than happy to further assist you with your queries.
Thanks,
Carly
You need an adapter - an RCA-to-HDMI converter. Something like this:
https://www.amazon.com/Converter-Amtake-Composite-Adapter-Supporting/dp/B07MJTR9KS/
Make sure you get one from a place with a good return policy as these things can be hit or miss or you may not be completely satisfied with the results. Note that they make HDMI-to-RCA and RCA-to-HDMI. They're not equivalent and you need the latter.
One other option that won't require any adapter is to connect a coax cable from your VHS player to the TV's antenna input and then change to channel 3 or 4 on the TV, as appropriate, when you want to use the VHS player.