The easy way: wire it to a socket you can plug your shore power cord into.
The harder but possibly more convenient way: obtain a transfer switch of some sort and install it such that it switches the main power input to the electric panel between the inverter and the shore power cord.
The inverter may have some sort of a transfer switch built into it already, in which case it could also be wired so that (typically) one or two branch circuits go through it and are switched between shore power and inverter power that way. Using the built-in transfer switch you're typically not able to switch the entire electric service, as it usually doesn't have sufficiently high ratings.
Do not simply connect the inverter and the RV power directly without some sort of a transfer switching arrangement. Doing so is dangerous: it leaves the exposed male end of the shore power cord/connector energized when the inverter is on, and plugging into a shore power connection or a generator will damage the inverter (at least if the inverter is on, and quite possibly just if its connected in, depending on the design).