Random error on allocating element when Click Element

The description SeleniumTestability sounds great.
I installed accordingly documentation, remove selenium2library.
pip list | grep selenium
robotframework-seleniumlibrary 5.1.3
robotframework-seleniumtestability 1.1.0
selenium 4.0.0

[ ERROR ] Error in file ‘/Users/abc/development/project-ui-autotest/Resources/resource.robot’ on line 3: Initializing library ‘SeleniumLibrary’ with arguments [ plugins=SeleniumTestability;True;30 Seconds;True ] failed: Importing test library ‘SeleniumTestability’ failed: AttributeError: type object ‘DesiredCapabilities’ has no attribute ‘PHANTOMJS’
Traceback (most recent call last):
File “/Users/abc/venvs/project-auto/lib/python3.9/site-packages/SeleniumTestability/init.py”, line 2, in
from .plugin import SeleniumTestability
File “/Users/abc/venvs/project-auto/lib/python3.9/site-packages/SeleniumTestability/plugin.py”, line 43, in
class SeleniumTestability(LibraryComponent):
File “/Users/abc/venvs/project-auto/lib/python3.9/site-packages/SeleniumTestability/plugin.py”, line 148, in SeleniumTestability
“phantomjs”: DesiredCapabilities.PHANTOMJS,
PYTHONPATH:
/Users/abc/venvs/project-auto/bin
/Library/Frameworks/Python.framework/Versions/3.9/lib/python39.zip
/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9
/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/lib-dynload
/Users/abc/venvs/project-auto/lib/python3.9/site-packages
Tests.Search


Base search works properly | FAIL |
Parent suite setup failed:
No keyword with name ‘Open Browser’ found.


Tests.Search | FAIL |
Suite setup failed:
No keyword with name ‘Open Browser’ found.

Also suite teardown failed:
No keyword with name ‘Close All Browsers’ found.

1 test, 0 passed, 1 failed


Tests | FAIL |
10 tests, 0 passed, 10 failed