Modals are:
The modal verbs are:
can/could may/might shall/should will/would must
We use modal verbs to show if we believe something is certain, probable or possible (or not). We also use modals to do things like talking about ability, asking permission making requests and offers, and so on.
British Council definition of a modal verbs
They are not categorized alongside irregular verbs. They have their own logic. They are used alongside another main verb: should go, mustn't go, might be, etc.
These days they will not allow us to walk into that room.
That sentence means: We are not permitted to walk into that room. Also, please note the main verb is allow. Will is the modal form, yes. AndBut will is also an auxiliary verb and often shows intention about the future. And in a sense, it means as of "these days". From this time forward. In that sense, it is a future idea.
They will not allow us to enter that room [in the future] even though they did yesterday.
Please note: this explanation is not for the verb to will someone to do something,which is a regular verb:will/willed/willed.