Clarifiction with FXS and FXO modules

Hello. I was able to salvage a Octal Analog Series A8B card from e-waste and am looking to possibly use it with our local food bank. It currently has two X400M modules installed. Since these are FXO modules that would mean that the card would be able to handle 8 lines coming in from the phone company, but could not handle any analog phones we have here as extensions correct? That also means that the card could be used to connect the PSTN lines to any VOIP handsets we may acquire to use as extensions.

In order to be able to use our existing analog devices I would need either the FXS module for the card or another FXS card to handle it.

Do I have things right or can the x400m module be used for analog extensions?

I don’t know that card but if you want to use analog phone as SIP endpoints, you need or use FXS module or use SIP ATA. Related to the x400m module is better if you contact the card vendor directly