You can only import from/export to a locally attached volume. The Apple Photos app syncs to iCloud just like the your Lightroom app syncs to the Adobe cloud. Your Macbook Air Photos are hidden inside the "Photos Library.photoslibrary" package. Lightroom can not directly access these hidden folders to import . To get to them, you first need to open the package and copy the folder found there named "originals" to a folder accessible by Lightroom.
Files in your Flickr account web site need to be downloaded to a local folder before that can be imported into Lightroom.
Flickr also needs you to export a derivative file (i.e.one edited in Lightroom) to a local folder. From there you can send these files to Flickr in the usual way.
Some alternatives:
I have found that Apple Cloud and Adobe Cloud do not play well together. For that reason I have uninstalled the Photos app on my iMac and do not use it. On my mobile devices, I use the Lightroom app (and Lightroom camera) to import directly into Lightroom (mobile). You can also designate a Lightroom (mobile) album to "auto Add" from the Camera Roll. Doing that, all mobile photos automatically show up in Lightroom.
Flickr is not designed to accept bulk imports from apps like Lightroom . Flickr has lost (for me) its original appeal. Instead of making it easier to add and curate your photos, over time they have made it more difficult. Because of this, I have not used Flickr for years and at one time that was my primary outlet for sharing my images with others. I would suggest an alternative. With your Subscription plan, you have an app and a dedicated website called Portfolio. (portfolio.adobe.com). There you can build you own website with an option to have your own domain name. In Portfolio, you create sub pages from your Lightroom albums. Here is a link to mine:
https://cletuslee.work. Except for the optional personal domain name. All of Portfolio is free with your subscription. Registering the optional domain name with a third party registrar is less than $10 annually.