A similar part is the LM3875TF/NOPB, which is in the Multisim database in the AUDIO_AMPFLIER family under the Analog group, you can use that if it fits your needs. Otherwise you may be able to find a SPICE model for the LM386 by searching Google and from there you can create a custom Multisim component. You can use this tutorial as a guide: https://knowledge.ni.com/KnowledgeArticleDetails?id=kA03q000000YH5fCAG&l=en-US
