This is from the USCCB’s website, not the GIRM, but it is a description of the GIRM (I can’t ever find a good online resource for the GIRM).
- It is for the priest celebrant to direct this prayer from the chair. He himself begins it with a brief introduction, by which he invites the faithful to pray, and likewise he concludes it with a prayer. The intentions announced should be sober, be composed freely but prudently, and be succinct, and they should express the prayer of the entire community.
The intentions are announced from the ambo or from another suitable place, by the deacon or by a cantor, a lector, or one of the lay faithful.68
The people, however, stand and give expression to their prayer either by an invocation said together after each intention or by praying in silence.
The website is: usccb.org/liturgy/current/chapter2.shtml#sect1
It doesn’t say that the faithful MUST say “Lord, hear our prayer”.