Problems doing a new install on a generic Drupal 8.9.2 installation

[kenrbnsn]

I spun up a new Drupal 8.9.2 site to test out ui_patterns and ui_patterns_pattern_lab.

When I do
$ composer require drupal/ui_patterns drupal/ui_patterns_pattern_lab
I first got this error:
Not scaffolding files for drupal/ui_patterns, because it is not listed in the element 'extra.drupal-scaffold.allowed-packages' in the root-level composer.json file.
So I put it in that section. Now, I'm getting:
Package drupal/ui_patterns has scaffold operations, and is already allowed in the root-level composer.json file. The allowed package drupal/ui_patterns does not provide a file mapping for Composer Scaffold.

Before that error, I got these lines:

Using version ^1.2 for drupal/ui_patterns
Using version ^1.0@alpha for drupal/ui_patterns_pattern_lab
./composer.json has been updated
Loading composer repositories with package information
Updating dependencies (including require-dev)
Package operations: 5 installs, 0 updates, 0 removals
  - Installing michelf/php-markdown (1.9.0): Loading from cache
  - Installing spatie/yaml-front-matter (2.0.5): Loading from cache
  - Installing drupal/ui_patterns (1.2.0): Loading from cache
  - Installing drupal/ui_patterns_library (1.2.0)
  - Installing drupal/ui_patterns_pattern_lab (1.0.0-alpha5): Loading from cache

Shouldn't this infomation be provided by the package? How do I get around this problem