JSON

DEBUG: wp_remote_get to https://safetytrainingseminars.enrollware.com/reg/calendar-feed.ashx?loc=114678&start=2022-01-30&end=2022-03-06&_=1643796334387
DEBUG: arguments: Array ( [timeout] => 5 )
DEBUG: success getting URL

If you use WordPress without Gutenberg, you can use this Shortcode (copy with Strg+A, paste to TEXT-editor!):
DEBUG: Cache is NOT active<br>DEBUG: try to retieve this url: https://safetytrainingseminars.enrollware.com/reg/calendar-feed.ashx?loc=114678&start=2022-01-30&end=2022-03-06&_=1643796334387<br>DEBUG: wp_remote_get to https://safetytrainingseminars.enrollware.com/reg/calendar-feed.ashx?loc=114678&start=2022-01-30&end=2022-03-06&_=1643796334387<br>DEBUG: arguments: Array ( [timeout] => 5 ) <br>DEBUG: success getting URL<br><br>DEBUG: api-answer:<br>Inspect JSON: Copypaste (click in box, Strg-A marks all, then insert into clipboard) the JSON from the following box to <a href="https://jsoneditoronline.org" target=_blank>https://jsoneditoronline.org</a>):<br><textarea rows=7 cols=90>[{"id":6087509,"title":"\u003cb\u003e9:00am\u003c/b\u003e\u003cbr /\u003eBLS (Renewal or Initial)","start":"2022-02-28T09:00:00.0000000","end":null,"url":null,"allDay":false,"className":"past-class","description":null},{"id":5712091,"title":"\u003cb\u003e12:00pm\u003c/b\u003e\u003cbr /\u003eBLS (Renewal or Initial)","start":"2022-03-01T12:00:00.0000000","end":null,"url":null,"allDay":false,"className":"past-class","description":null}]
DEBUG: basenode: id
DEBUG: template:
<b>Empty template: Add some text!</b><br> For the example copypaste this to the right Template box:<br>start: &#123;start&#125;&lt;br&gt; &#123;subloop-array:level2:-1&#125; level2: &#123;level2.key&#125; &lt;br&gt;&#123;subloop:level2.data:-1&#125; id: &#123;level2.data.id&#125;, type: &#123;level2.data.type&#125;&lt;br&gt; &#123;/subloop:level2.data&#125; &#123;/subloop-array:level2&#125;
DEBUG:
LEAVE function checkType // depth: 1 // result: <b>Empty template: Add some text!</b><br> For the example copypaste this to the right Template box:<br>start: &#123;start&#125;&lt;br&gt; &#123;subloop-array:level2:-1&#125; level2: &#123;level2.key&#125; &lt;br&gt;&#123;subloop:level2.data:-1&#125; id: &#123;level2.data.id&#125;, type: &#123;level2.data.type&#125;&lt;br&gt; &#123;/subloop:level2.data&#125; &#123;/subloop-array:level2&#125; <b>Empty template: Add some text!</b><br> For the example copypaste this to the right Template box:<br>start: &#123;start&#125;&lt;br&gt; &#123;subloop-array:level2:-1&#125; level2: &#123;level2.key&#125; &lt;br&gt;&#123;subloop:level2.data:-1&#125; id: &#123;level2.data.id&#125;, type: &#123;level2.data.type&#125;&lt;br&gt; &#123;/subloop:level2.data&#125; &#123;/subloop-array:level2&#125;
// returnHTMLinsideProc:

DEBUG: result:


api-answer:
Inspect JSON: Copypaste (click in box, Strg-A marks all, then insert into clipboard) the JSON from the following box to https://jsoneditoronline.org):
[{“id”:6087509,”title”:”\u003cb\u003e9:00am\u003c/b\u003e\u003cbr /\u003eBLS (Renewal or Initial)”,”start”:”2022-02-28T09:00:00.0000000″,”end”:null,”url”:null,”allDay”:false,”className”:”past-class”,”description”:null},{“id”:5712091,”title”:”\u003cb\u003e12:00pm\u003c/b\u003e\u003cbr /\u003eBLS (Renewal or Initial)”,”start”:”2022-03-01T12:00:00.0000000″,”end”:null,”url”:null,”allDay”:false,”className”:”past-class”,”description”:null}]
template:
<b>Empty template: Add some text!</b><br> For the example copypaste this to the right Template box:<br>start: {start}<br> {subloop-array:level2:-1} level2: {level2.key} <br>{subloop:level2.data:-1} id: {level2.data.id}, type: {level2.data.type}<br> {/subloop:level2.data} {/subloop-array:level2}
result:

result of parsing is empty: no data to be displayed.
Check JSON and template, please.