I'd click on the Live Chat at http://shop.panasonic.com/support-only/TC-P55ST30.html if you lost yours.
But if this was mine I'd use the usual WiFi to Ethernet client devices. There are dozens of models so without any searching I'll supply one so you can ask their maker how it works.
https://www.amazon.com/NETGEAR-Universal-Ethernet-Adapter-WNCE3001/dp/B005N6XBDO
I have a Panasonic TV Plasma 55" model no: TH-P55ST30S.
I'm looking for a wifi adaptor from the search engine and I couldn't get any one of them for this model. Please advice where I can get this or is there any other model which is compatible with my model.

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