System.CalloutException: Uncommitted Work Pending with Einstein Prompt Template and HTTP Callout

I'm getting a System.CalloutException: You have uncommitted work pending error when making an HTTP callout after calling ConnectApi.EinsteinLLM.generateMessagesForPromptTemplate. No DML operations are present in my code, and removing the Einstein call resolves the issue. 

Here’s the relevant code: 

public class MyClass {    public void einsteinCall(String text) {        ConnectApi.WrappedValue propertyValue = new ConnectApi.WrappedValue();        propertyValue.value = text;        Map<String, ConnectApi.WrappedValue> inputParams = new Map<String, ConnectApi.WrappedValue>();        inputParams.put('Input:input', propertyValue);        ConnectApi.EinsteinPromptTemplateGenerationsInput executeTemplateInput = new ConnectApi.EinsteinPromptTemplateGenerationsInput();        executeTemplateInput.additionalConfig = new ConnectApi.EinsteinLlmAdditionalConfigInput();        executeTemplateInput.additionalConfig.applicationName = 'PromptBuilderPreview';        executeTemplateInput.isPreview = false;        executeTemplateInput.inputParams = inputParams;        ConnectApi.EinsteinPromptTemplateGenerationsRepresentation generationsOutput = ConnectApi.EinsteinLLM.generateMessagesForPromptTemplate(            PROMPT_TEMPLATE_NM,            executeTemplateInput        );        ConnectApi.EinsteinLLMGenerationItemOutput response = generationsOutput.generations[0];         String op = response.text;        op = op.replace('<output>', '').replace('</output>', '').replaceAll('```json', '').replace('```', '');        System.debug('Prompt Template response: ' + op);         PromptResponse promptResult = (PromptResponse) JSON.deserialize(op, PromptResponse.class);        System.debug('Prompt Template response: ' + promptResult.toString());     }    public void callEinsteinAndMakeCallout(String text) {        einsteinCall(text);        HttpRequest request = new HttpRequest();        request.setEndpoint('callout:msprodnc/v1/code');        request.setMethod('POST');        Http http = new Http();        HttpResponse response = http.send(request);        System.debug('HTTP Response: ' + response.getBody());    }}

Issue

The HTTP callout fails with System.CalloutException when preceded by einsteinCall.  

Without einsteinCall, the callout works. 

Questions

1. Does ConnectApi.EinsteinLLM.generateMessagesForPromptTemplate create pending work?
2. How can I commit the pending transaction so it allows http call ?