allow access to my zoom room

Welcome to the Zoom Community, @mfitness.

There are several scenarios for allowing someone else to host a meeting in your absence.  I think the Host Key  approach might be most appropriate for you to allow a client to run the meeting.

1. Scheduling Privilege is normally used when there's an assistant or a colleague who will need to substitute-host often. 
2. If you just need a one-off substitute and the substitute is on the same corporate account as you, the Alt-Host option might be more suited (and less work initially).
3. If one or the other is not true (not Licensed, or not on the same account), then your only option is the Host Key method.

Note that both Scheduling Privilege and Alt-Host methods require that both accounts be on the same account and both be Licensed (paid) accounts.  Only Host key will work if either of those requirements are not met.

See these Zoom Support articles for more information:

https://support.zoom.us/hc/en-us/articles/201362803-Using-scheduling-privilege

https://support.zoom.us/hc/en-us/articles/208220166-Designating-an-alternative-host

https://support.zoom.us/hc/en-us/articles/205172555-Using-your-host-key 

Scheduling Privilege Additional Info:

Scheduling Privilege can be set up one-way or bidirectionally. Often an executive just needs and assistant to be able to schedule meetings and occasionally start them in the exec's absence, so the exec sets up Scheduling Privilege to allow the assistant to do so. If two colleagues (like teaching faculty) frequently stand in for one another, then both would assign Scheduling Privilege to the other. This can also work for more than two individuals.

Alt-Host Additional Info:

The alternative host must start the meeting using the join link in an email sent to them by the host. The meeting will not display in the upcoming meetings list in the desktop client, mobile app, or web page for alternative hosts.

Note that the person to whom Scheduling Privilege is assigned will have an additional drop-down to display either just their own meetings, just the other person's meeting, or all of them.

Host Key Additional Info:

Essentially, locate (and if desired, edit) your Host Key from your profile on the Zoom Web Portal. Set your meeting up with a Passcode, disabled Waiting Rooms, and enable Join Before Host (I recommend 15 minutes). Give your Host Key to your "substitute host", who will enter the room and use the Claim Host menu to become the host.