Getting error while POST request with large payload

Question

Facing this issue when I am passing a large(66kb) payload with a POST request. It works for a smaller payload.

PS: I am using http in the request as suggested by the other answers.

o.apache.coyote.http11.Http11Processor   : Error parsing HTTP request header
 Note: further occurrences of HTTP request parsing errors will be logged at DEBUG level.

java.lang.IllegalArgumentException: Invalid character found in method name. HTTP method names must be tokens
    at org.apache.coyote.http11.Http11InputBuffer.parseRequestLine(Http11InputBuffer.java:415) ~[tomcat-embed-core-9.0.21.jar!/:9.0.21]
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:294) ~[tomcat-embed-core-9.0.21.jar!/:9.0.21]
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) [tomcat-embed-core-9.0.21.jar!/:9.0.21]
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:853) [tomcat-embed-core-9.0.21.jar!/:9.0.21]
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1587) [tomcat-embed-core-9.0.21.jar!/:9.0.21]
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-9.0.21.jar!/:9.0.21]
    at datadog.trace.bootstrap.instrumentation.java.concurrent.Wrapper.run(Wrapper.java:25) [na:0.79.0]
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [na:1.8.0_211]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_211]
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-9.0.21.jar!/:9.0.21]
    at java.lang.Thread.run(Thread.java:748) [na:1.8.0_211]```