Can we do API chaining in the Robotframework for the RestAPI's

My 1st Case is a Post Request then i need to save a key from the response & pass it into the 2nd request which is a Get Request. does it possible?

I could able to do the same in the Postman like declaring those as a variable either globally or colection basics.

Yes, you can.

Just read the documentation of RequestsLibrary.

Yes i have tried but my first request is post so i need to pass the content type but the second is GET it doesn’t need content type so my application is throwing 500 as error

Even i tried to add a seperate header again

create session sms ${base_url}
${destination_list}= Create List +919112312345
${body}= Create Dictionary source=${source} destination=${destination_list} body=${body1}
${header}= Create Dictionary Account-Sid=${Account-Sid} Api-Key=${Api-Key} Api-Secret=${Api-Secret} Content-Type=application/json
${header1}= Create Dictionary Account-Sid=${Account-Sid} Api-Key=${Api-Key} Api-Secret=${Api-Secret}
#Sending SMS
${response}= Post Request sms /sms data=${body} headers=${header}

Status Should Be    200
Log To Console    ${response.status_code}
#Should Be Equal   ${response.json()}[destinations][0][status]  INPROGRESS
Log To Console    ${response.content}
Log To Console    ${response.json()}[messageId]
#Log To Console    ${response.json()}[status]

# Log response and fetch status via GET
${header}=  Create Dictionary  Account-Sid=${Account-Sid}  Api-Key=${Api-Key}  Api-Secret=${Api-Secret}
${response}=  GET On Session  sms  ${base_url}/sms/${response.json()}[messageId]

Now i have chained the request but for me after the post request there should be some delay to run Get request like 100 to 500 ms is it possible?

You could try a Wait Until Keyword Succeeds to just repeat your GET request until it is successful.
A hard coded sleep also works, but this is something I typically avoid.

By the way:
Here is also some example REST API tests where the requests are connected.

Create a Booking at Restful Booker
    ${booking_dates}    Create Dictionary    checkin=2022-12-31    checkout=2023-01-01
    ${body}    Create Dictionary    firstname=Hans    lastname=Gruber    totalprice=200    depositpaid=false    bookingdates=${booking_dates}
    ${response}    POST    url=    json=${body}
    ${id}    Set Variable    ${response.json()}[bookingid]
    ${response}    GET${id}

Here you can also see hot a id variable is read from the response.
And afterwards the ${id} variable is used for another GET request.

glad it worked and i also tried with sleep both has been worked @Many thank you so much