[Solved] [ThingSpeak] - How to retrieve the time since the last record

Hi,
Due to the fact that in the free version of ThingSpeak there is a limitation on the frequency of records, I am trying to develop a method to synchronise several separate modules transmitting to the same channel.
I don't want to get into NTP for now, as I'm a strong beginner.
I have come up with an idea, but in order to do so, I need a feedback from the server about the time elapsed since the last write in seconds.
Is there any way to extract this from the server?
I know it is possible to download the data into .json or .xml, but how do I further extract what I need from this? As long as I can find the data there at all.

Greetings
grzechoo

Added after 12 [minutes]:

Hello again and apologies .
I've already found it after I let the post go, but maybe it will be useful to someone else:

https://uk.mathworks.com/help/thingspeak/readlastentryage.html

An additional question arises here, however, because I keep getting a "-1" return, i.e. no access.

Does this method only work on public channels?

Greetings
sinoo

Hi,
Due to the fact that in the free version of ThingSpeak there is a limitation on the frequency of records, I am trying to develop a method to synchronise several separate modules transmitting to the same channel.
I don't want to get into NTP for now, as I'm a strong beginner.
I have come up with an idea, but in order to do so, I need a feedback from the server about the time elapsed since the last write in seconds.
Is there any way to extract this from the server?
I know it is possible to download the data into .json or .xml, but how do I further extract what I need from this? As long as I can find the data there at all.

Greetings
grzechoo

Added after 12 [minutes]:

Hello again and apologies .
I've already found it after I let the post go, but maybe it will be useful to someone else:

https://uk.mathworks.com/help/thingspeak/readlastentryage.html

An additional question arises here, however, because I keep getting a "-1" return, i.e. no access.

Does this method only work on public channels?

Greetings
sinoo

Added after 8 [minutes]:

https://api.thingspeak.com/channels/{channelID}/feeds/last_data_age.txt?api_key={read API key}