How do I get Selenium in Python to select a dropdown that doesn't appear to have <select> and <option> tags?

The code for the website's dropdown is:

<div id="ctl00_MainContent_basicSettingsCntrl_divAddressVerficationLbl" class="rowLeftPad50 label" data-argosy-tooltip="25">
        Address Verification
</div>
<div id="ctl00_MainContent_basicSettingsCntrl_divAddressVerficationCombo" class="rowLeft ">
     <div id="ctl00_MainContent_basicSettingsCntrl_rdComboAddressVerification" class="RadComboBox RadComboBox_Default" style="width:153px;white-space:normal;">
	<table summary="combobox" style="border-width:0;border-collapse:collapse;width:100%">
		<tr class="rcbReadOnly">
			<td style="width:100%;" class="rcbInputCell rcbInputCellLeft"><input name="ctl00$MainContent$basicSettingsCntrl$rdComboAddressVerification" type="text" class="rcbInput radPreventDecorate" id="ctl00_MainContent_basicSettingsCntrl_rdComboAddressVerification_Input" value="Yes" readonly="readonly" tabindex="7" /></td>
			<td class="rcbArrowCell rcbArrowCellRight"><a id="ctl00_MainContent_basicSettingsCntrl_rdComboAddressVerification_Arrow" style="overflow: hidden;display: block;position: relative;outline: none;">select</a></td>
		</tr>
	</table>
	<div class="rcbSlide" style="z-index:6000;"><div id="ctl00_MainContent_basicSettingsCntrl_rdComboAddressVerification_DropDown" class="RadComboBoxDropDown RadComboBoxDropDown_Default " style="display:none;"><div class="rcbScroll rcbWidth" style="width:100%;"><ul class="rcbList" style="list-style:none;margin:0;padding:0;zoom:1;"><li class="rcbItem ">Yes</li><li class="rcbItem ">No</li></ul></div></div></div><input id="ctl00_MainContent_basicSettingsCntrl_rdComboAddressVerification_ClientState" name="ctl00_MainContent_basicSettingsCntrl_rdComboAddressVerification_ClientState" type="hidden" />
</div>
    </div>
</div>

From the guides I've seen on Selenium, most of them are accessing a dropdown that has a Select tag, with options have an option tag. I'm guessing this dropdown is created or maintained in javascript? Is there a way to manipulate this using Selenium? Or can I use something else within Python to change the dropdown?

Here's my relevant code, most recently when I tried a workaround to simply use sending an ARROW_UP key to select something else, which throws an error:

#find and click dropdown
driver.find_element(By.ID, "ctl00_MainContent_basicSettingsCntrl_rdComboAddressVerification").click()
element = driver.find_element(By.ID, "ctl00_MainContent_basicSettingsCntrl_rdComboAddressVerification") 
#will move selector up to yes. If already at top, will remain at top
element.send_keys(Keys.ARROW_UP)    
#click submit
driver.find_element(By.ID, "btnSaveCustomerDetails").click()    

The usual Select does not work for obvious reasons, at least from what I've tried from a few various guides on youtube and the Selenium documentation. I am not seeing a way to interact with it in general.

I thought I might have a workaround- to simply send an ARROW_UP to select the above item in the list but it throws an error: selenium.common.exceptions.ElementNotInteractableException: Message: element not interactable

Most likely, you will need to create an XPath locator to locate the
<span class="k-icon k-i-arrow-60-down"></span> element inside the "fancybox". Perhaps something like this:

//div[@class='fancybox-outer']//span[@class='k-icon k-i-arrow-60-down']

Once you obtain this element, send a click to it to expand.

Next, locate the list items. Use an explicit wait to set timeout and wait for elements to be visible. Lastly, locate the desired listed element and click on it. For the example in the comments, you could locate the desired listed item by its data-offset-index attribute. For example, to select the second listed item, you will need an expression like this

//div[@class='fancybox-outer']/following::ul/li[@data-offset-index="2"]

The reason for this is because the list is not nested inside the "fancybox." It is actually after this element. The following XPath axes uses a relative position (in this case the "fancybox" element) an searches for the given element that exist only after the base element. In essence, you are looking for a ul element that exist after the "fancybox" that contains an li element with the given data_offset_index.